Delivery system and method for bifurcated graft

ABSTRACT

A flexible low profile delivery system for delivery of an expandable intracorporeal device, specifically, an endovascular graft, which has at least one belt circumferentially disposed about the device in a constraining configuration. The belt is released by a release member, such as a release wire, by retracting the wire from looped ends of the belt. Multiple belts can be used and can be released sequentially so as to control the order of release and placement of the endovascular graft. An outer protective sheath may be disposed about the endovascular graft while in a constrained state which must first be retracted or otherwise removed prior to release of the graft from a constrained state. The delivery system can be configured for delivery over a guiding device such as a guidewire. The delivery system can also be configured for delivery of bifurcated intracorporeal devices.

RELATED APPLICATIONS

[0001] This application is a continuation-in-part of U.S. patentapplication Ser. No. 09/917,371, filed Jul. 27, 2001, by Michael V.Chobotov et aL., entitled “Delivery System and Method for BifurcatedEndovascular Graft”, which is a continuation-in-part of U.S. patentapplication, Ser. No. 09/834,278, filed Apr. 11, 2001, by Michael V.Chobotov et aL, entitled “Delivery System and Method for EndovascularGraft,” Each application is hereby incorporated by reference herein inits entirety.

BACKGROUND

[0002] The present invention relates generally to a system and methodfor the treatment of disorders of the vasculature. More specifically, asystem and method for treatment of thoracic or abdominal aortic aneurysmand the like, which is a condition manifested by expansion and weakeningof the aorta. Prior methods of treating aneurysms have consisted ofinvasive surgical methods with graft placement within the affectedvessel as a reinforcing member of the artery. However, such a procedurerequires a surgical cut down to access the vessel, which in turn canresult in a catastrophic rupture of the aneurysm due to the decreasedexternal pressure from the surrounding organs and tissues, which aremoved during the procedure to gain access to the vessel. Accordingly,surgical procedures can have a high mortality rate due to thepossibility of the rupture discussed above in addition to other factors.Other risk factors for surgical treatment of aortic aneurysms caninclude poor physical condition of the patient due to blood loss,anuria, and low blood pressure associated with the aortic abdominalaneurysm. An example of a surgical procedure is described in a bookentitled Surgical Treatment of Aortic Aneurysms by Cooley published in1986 by W.B. Saunders Company.

[0003] Due to the inherent risks and complexities of surgicalintervention, various attempts have been made to develop alternativemethods for deployment of grafts within aortic aneurysms. One suchmethod is the non-invasive technique of percutaneous delivery by acatheter-based system. Such a method is described in Lawrence, Jr. etal. in “Percutaneous endovascular graft: experimental evaluation”,Radiology (May 1987). Lawrence described therein the use of a Gianturcostent as disclosed in U.S. Pat. No. 4,580,568. The stent is used toposition a Dacron fabric graft within the vessel. The Dacron graft iscompressed within the catheter and then deployed within the vessel to betreated. A similar procedure has also been described by Mirich et al. in“Percutaneously placed endovascular grafts for aortic aneurysms:feasibility study,” Radiology (March 1989). Mirich describes therein aself-expanding metallic structure covered by a nylon fabric, with saidstructure being anchored by barbs at the proximal and distal ends.

[0004] One of the primary deficiencies of the existing percutaneousdevices and methods has been that the grafts and the delivery systemsused to deliver the grafts are relatively large in profile, often up to24 French, and stiff in longitudinal bending. The large profile andrelatively high bending stiffness of existing delivery systems makesdelivery through the vessels of a patient difficult and can pose therisk of dissection or other trauma to the patient's vessels. Inparticular, the iliac arteries of a patient are often too narrow orirregular for the passage of existing percutaneous devices. Because ofthis, non-invasive percutaneous graft delivery for treatment of aorticaneurysm is contraindicated for many patients who would otherwisebenefit from it.

[0005] What is needed is an endovascular graft and delivery systemhaving a small outer diameter relative to existing systems and highflexibility to facilitate percutaneous delivery in patients who requiresuch treatment. What is also needed is a delivery system for anendovascular graft that is simple, reliable and that can accurately andsafely deploy an endovascular graft within a patient's body, lumen orvessel.

SUMMARY

[0006] The invention is directed generally to a delivery system fordelivery of an expandable intracorporeal device, specifically, anendovascular graft. Embodiments of the invention are directed topercutaneous non5 invasive delivery of endovascular grafts whicheliminate the need for a surgical cut-down in order to access theafflicted artery or other intracorporeal conduit of the patient beingtreated. Such a non-invasive delivery system and method result inshorter procedure duration, expedited recovery times and lower risk ofcomplication. The flexible low profile properties of some embodiments ofthe invention also make percutaneous non-invasive procedures fordelivery of endovascular grafts available to patient populations thatmay not otherwise have such treatment available. For example, patientswith small anatomies or particularly tortuous vasculature may becontraindicated for procedures that involve the use of delivery systemsthat do not have the flexible or low profile characteristics ofembodiments of the present invention.

[0007] In one embodiment, the delivery system has an elongate shaft witha proximal section and a distal section. The distal section of theelongate shaft includes a portion having an expandable intracorporealdevice. An elongate belt support member is disposed adjacent a portionof the expandable intracorporeal device and a belt is secured to thebelt support member and circumferentially disposed about the expandableintracorporeal device. The belt member constrains at least a portion ofthe expandable intracorporeal device. A release member releasablysecures the belt in the constraining configuration.

[0008] Another embodiment of the invention is directed to a deliverysystem that has an elongate shaft with a proximal section and a distalsection. The distal section of the elongate shaft has an elongate beltsupport member disposed adjacent a portion of the expandableintracorporeal device. A belt is secured to the belt support member andis circumferentially disposed about the expandable intracorporealdevice. The belt has a configuration which constrains the expandableintracorporeal device and a release member releasably secures the beltin the constraining configuration. The belt may constrain any portion ofthe expandable intracorporeal device, such as a self-expanding portionof the expandable intracorporeal device. A self-expanding portion of thedevice may include a self-expanding member such as a tubular stent.

[0009] In a particular embodiment of the invention, a plurality of beltsare secured to various axial positions on the belt support member, arecircumferentially disposed about the expandable intracorporeal deviceand have a configuration which constrains the expandable intracorporealdevice. At least one release member releasably secures the belts in theconstraining configuration. Each belt can be released by a singleseparate release member which engages each belt separately, or multiplebelts can be released by a single release member. The order in which thebelts are released can be determined by the axial position of the beltsand the direction of movement of the release member.

[0010] Another embodiment of the invention is directed to a deliverysystem for delivery of a self-expanding endovascular graft with aflexible tubular body portion and at least one self-expanding membersecured to an end of the endovascular graft. The delivery system has anelongate shaft having a proximal section and a distal section. Thedistal section of the elongate shaft has an elongate belt support memberdisposed within the self-expanding member of the endovascular graft anda belt that is secured to the belt support member adjacent theself-expanding member. The belt is also circumferentially disposed aboutthe self-expanding member and has a configuration that constrains theself-expanding member. A release wire releasably secures ends of thebelt in the constraining configuration.

[0011] A further embodiment of the invention includes a delivery systemfor delivery of an endovascular graft with a flexible tubular bodyportion and a plurality of self-expanding members secured to ends of theendovascular graft. The delivery system has an elongate shaft with aproximal section and a distal section. The distal section of theelongate shaft has an elongate guidewire tube disposed within theendovascular graft in a constrained state. A plurality of shape memorythin wire belts are secured to the guidewire tube respectively adjacentthe self-expanding members. The belts are circumferentially disposedabout the respective self-expanding members and have a configurationthat constrains the respective self-expanding members. A first releasewire releasably secures ends of the belts disposed about theself-expanding members at the proximal end of the endovascular graft ina constraining configuration. A second release wire releasably securesends of the belts disposed about the self-expanding members at a distalend of the endovascular graft in the constraining configuration.

[0012] The invention also is directed to a method for deploying anexpandable intracorporeal device within a patient's body. The methodincludes providing a delivery system for delivery of an expandableintracorporeal device including an elongate shaft having a proximalsection and a distal section. The distal section of the elongate shafthas an elongate belt support member disposed adjacent a portion of theexpandable intracorporeal device and a belt which is secured to the beltsupport member. The belt is circumferentially disposed about theexpandable intracorporeal device and has a configuration that constrainsthe expandable intracorporeal device. A release member releasablysecures the belt in the constraining configuration.

[0013] Next, the distal end of the delivery system is introduced intothe patient's body and advanced to a desired site within the patient'sbody. The release member is then activated, releasing the belt from theconstraining configuration. Optionally, the delivery system may alsohave an outer protective sheath disposed about the endovascular graft ina constrained state, the belt in its constraining configuration and atleast a portion of the release wire disposed at the belt. In such anembodiment, the method of deployment of an expandable intracorporealdevice also includes retraction of the outer protective sheath from theendovascular graft prior to activation of the release member.

[0014] In an embodiment of the invention directed to delivery ofbifurcated intracorporeal device, an elongate shaft has a proximalsection and a distal section. The distal section of the shaft has anelongate primary belt support member and at least one primary beltdisposed on the primary belt support member. The primary belt supportmember is configured to be circumferentially disposed about a bifurcatedintracorporeal device and at least partially constrain the device. Aprimary release member is configured to engage and releasably secure theprimary belt in a constraining configuration. At least one elongatesecondary belt support member is disposed adjacent the elongate primarybelt support member. At least one secondary belt is disposed on thesecondary belt support member. This at least one secondary belt isconfigured to be circumferentially disposed about a bifurcatedintracorporeal device and at least partially constrain the device. Asecondary release member is configured to engage and releasably securethe secondary belt in a constraining configuration.

[0015] In a method for deploying a bifurcated intracorporeal devicewithin a patient's body, a delivery system for delivery and deploymentof a bifurcated intracorporeal device is provided. The delivery systemincludes an elongate shaft having a proximal section and a distalsection. The bifurcated intracorporeal device is disposed on the distalsection of the elongate shaft. The distal section of the elongate shaftalso includes an elongate primary belt support member and at least oneprimary belt secured to the primary belt support member. The primarybelt is configured to be circumferentially disposed about a bifurcatedintracorporeal device and at least partially constrain the device. Aprimary release member engages and releasably secures the primary beltin the constraining configuration. The distal section of the elongateshaft also includes at least one elongate secondary belt support memberdisposed adjacent the elongate primary belt support member. At least onesecondary belt is secured to the secondary belt support member and isconfigured to be circumferentially disposed about a bifurcatedintracorporeal device to at least partially constrain the device. Asecondary release member engages and releasably secures the secondarybelt in a constraining configuration.

[0016] The distal end of the delivery system is introduced into thepatient's body and advanced to a desired site within the patient's body.The release members are then activated to release the belts from theconstraining configuration and the device is deployed. Thereafter, thedelivery system can be removed from the patient's body. In someembodiments of the invention, the secondary belt support member isdetached and removed from the delivery system prior to withdrawal of thedelivery system from the patient. In another embodiment, the secondarybelt support member is displaced laterally towards the primary beltsupport member so as to be substantially parallel to the primary beltsupport member and enable withdrawal of the delivery system through anipsilateral side of the bifurcated intracorporeal device.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1 is an elevational view in partial longitudinal sectionillustrating an embodiment of a delivery system for an expandableintracorporeal device having features of the invention.

[0018]FIG. 2 is a transverse cross sectional view of the delivery systemof FIG. 1 taken along lines 2-2 of FIG. 1.

[0019]FIG. 3 is a transverse cross sectional view of the delivery systemof FIG. 1 taken along lines 3-3 of FIG. 1.

[0020]FIG. 4 is a transverse cross sectional view of the delivery systemof FIG. 1 taken along lines 4-4 of FIG. 1.

[0021]FIG. 5 is a transverse cross sectional view of the delivery systemof FIG. 1 taken along lines 5-5 of FIG. 1.

[0022]FIG. 6A is an enlarged elevational view in partial section of thedelivery system in FIG. 1.

[0023]FIG. 6B is an enlarged elevational view in partial section of thedelivery system of FIG. 1 with portions of the graft and self-expandingmembers cut away for clarity of view of the belt bushings.

[0024]FIG. 7A is a perspective view showing release belt configurationshaving features of the invention.

[0025]FIG. 7B is a perspective view showing an alternative embodiment ofrelease belts.

[0026]FIG. 7C is an end view showing an alternative embodiment ofrelease belts.

[0027]FIG. 7D is a perspective view of the embodiment of FIG. 7C.

[0028]FIG. 7E is an enlarged view of a particular coupling configurationbetween end loops of release belts.

[0029]FIG. 7F is a perspective view, partially cut away, of a particularembodiment of an end loop of a release belt.

[0030]FIG. 7G is a perspective view of an alternative embodiment of arelease belt.

[0031]FIG. 7H is a perspective view of an alternative embodiment of arelease belt.

[0032]FIG. 7I is a perspective view of an alternative embodiment of abranched release wire.

[0033]FIG. 7J is an end view showing an alternative embodiment of arelease belt.

[0034]FIG. 7K is a transverse cross sectional view showing thealternative embodiment of the release belt configuration of FIG. 7Jconstraining a self-expanding member.

[0035]FIG. 7L is a detail of the connection formed where a release wireis used with the alternative release belt embodiment of FIGS. 7J-7K.

[0036]FIG. 8 is an elevational view in partial section of the proximaladapter shown in FIG. 1.

[0037]FIG. 9 is a diagrammatic view of a patient's body illustrating thepatient's heart, aorta, iliac arteries, femoral arteries, and a deliverysystem having features of the invention disposed within the femoralartery and aorta.

[0038]FIG. 10 is a diagrammatic view of a delivery system havingfeatures of the invention disposed within an artery of a patient with anexpandable intracorporeal device being deployed within the artery.

[0039]FIG. 11 is a diagrammatic view of a delivery system havingfeatures of the invention disposed within an artery of a patient with anexpandable intracorporeal device being deployed within the artery.

[0040]FIG. 12 is an enlarged diagrammatic view of a delivery systemhaving features of the invention disposed within an artery of a patientwith an expandable intracorporeal device being deployed within theartery.

[0041]FIG. 13 is an elevational view in partial section of a connectionbetween an inflation tube and an inflation port of an endovasculargraft.

[0042]FIG. 14 is an elevational view in partial longitudinal sectionillustrating an embodiment of a delivery system for an expandableintracorporeal device having features of the invention.

[0043]FIG. 15 is a transverse cross sectional view of the deliverysystem of FIG. 14 taken along lines 15-15 in FIG. 14.

[0044]FIG. 16 is an enlarged elevational view in partial section of thedelivery system shown in FIG. 14.

[0045]FIG. 17 is an elevational view in partial section of the proximaladapter of the delivery system shown in FIG. 14.

[0046]FIG. 18 is an elevational view in partial section of analternative embodiment of the proximal adapter of the delivery systemshown in FIG. 14 with a nested handle configuration.

[0047]FIG. 19 is an elevational view of a bifurcated stent graftsuitable for delivery and deployment by embodiments of the invention.

[0048]FIG. 20 is a transverse cross sectional view of the stent graft ofFIG. 19 taken along lines 20-20 in FIG. 19.

[0049]FIG. 21 is a transverse cross sectional view of the stent graft ofFIG. 19 taken along lines 21-21 of FIG. 19.

[0050]FIG. 22 is a transverse cross sectional view of the stent graft ofFIG. 19 taken along lines 22-22 of FIG. 19.

[0051]FIG. 23 is an elevational view in partial section of an embodimentof a delivery system having features of the invention.

[0052]FIG. 24 is a transverse cross sectional view of the deliverysystem of FIG. 23 taken along lines 24-24 of FIG. 23.

[0053]FIG. 25 is a transverse cross sectional view of the deliverysystem of FIG. 23 taken along lines 25-25 of FIG. 23.

[0054]FIG. 26 is an elevational view in partial section showing anenlarged view of a distal portion of the delivery system of FIG. 23.

[0055]FIG. 27 is a transverse cross sectional view of the deliverysystem of FIG. 26 taken along lines 27-27 of FIG. 26.

[0056]FIG. 28 is a transverse cross sectional view of the deliverysystem of FIG. 26 taken along lines 28-28 of FIG. 26.

[0057]FIG. 28A is a transverse cross sectional view of an alternativeembodiment of a secondary belt support member of a delivery systemsimilar in function to that shown in FIG. 28.

[0058]FIG. 28B is an elevational view of the alternative embodiment ofthe secondary belt support member of FIG. 28A.

[0059]FIG. 29 is a transverse cross sectional view of the deliverysystem of FIG. 26 taken along lines 29-29 of FIG. 26.

[0060]FIG. 30 is a transverse cross sectional view of the deliverysystem of FIG. 26 taken along lines 30-30 in FIG. 26.

[0061]FIG. 31 is an elevational view in partial section of the proximaladapter of the delivery system of FIG. 23.

[0062]FIG. 31A is an elevational view in partial section of the proximaladapter of the delivery system of FIG. 23, showing an optional ripcordand flexible fill cathether.

[0063]FIG. 31B is a simpler cross sectional schematic view of a bent orangled contralateral leg inflatable channel having a bead or lumenpatency member disposed in a channel lumen taken along line 31B-31B inFIG. 19.

[0064]FIG. 32 is a perspective view of the belt support member assemblyat a distal portion of the delivery system of FIG. 23.

[0065]FIG. 33 illustrates a portion of the internal vasculature of apatient, including the aorta, iliac and femoral arteries branchingtherefrom.

[0066]FIG. 34 is a magnified view of the abdominal aorta area of thepatient shown in FIG. 33 and shows a guidewire positioned in the aortafrom the right iliac artery.

[0067] FIGS. 35-37 illustrate the magnified view of the abdominal aortaof the patient shown in FIG. 33 and depict a deployment sequence of thebifurcated endovascular stent graft of FIG. 19 with the delivery systemof FIG. 23.

[0068]FIG. 37A is a perspective view of a marker disposed on thedelivery system distal section in the vicinity of the nosepiece.

[0069]FIG. 37B is a perspective view of an alternative embodiment of amarker for use in the delivery system of the present invention.

[0070] FIGS. 38-52 continue to illustrate a deployment sequence of thebifurcated endovascular stent graft of FIG. 19.

[0071] FIGS. 53-57 illustrate a number of alternative catheter distalshaft arrangements in which a well is provided to facilitate the orderlyand tangle-free withdrawal of the release strand from the deliverycatheter.

[0072] FIGS. 58-60 illustrate a further alternative belt support memberand contralateral leg delivery system configurations and operation.

DETAILED DESCRIPTION

[0073] FIGS. 1-8 and 10 illustrate an embodiment of delivery system 10for delivering a variety of expandable intracorporeal devices;specifically, an expandable endovascular graft 11. One such expandableendovascular graft 11 useful for delivery and deployment at a desiredsite within a patient is disclosed in co-pending U.S. patent applicationSer. No. 09/133,978, filed Aug. 14, 1998, by M. Chobotov, which ishereby incorporated by reference in its entirety.

[0074] Delivery system 10 in FIG. 1 has an elongate shaft 12 with aproximal section 13, a distal section 14, a proximal end 15 and a distalend 16. The distal section 14 has an elongate belt support member in theform of a guidewire tube 17 disposed adjacent a portion of theexpandable endovascular graft 11. A guidewire 18 is disposed withinguidewire tube 17. A plurality of belts 21, 22, and 23 are secured tothe guidewire tube 17 and are circumferentially disposed about portionsof the endovascular graft 11. FIG. 1 shows the belts in a configurationthat constrains the endovascular graft 11. First and second releasemembers 24 and 25 releasably secure belts 21, 22, and 23 in aconstraining configuration as shown.

[0075] The endovascular graft 11 has a proximal end 26, a distal end 27,a proximal inflatable cuff 28, a distal inflatable cuff 30, a proximalself-expanding member 31, a first distal self-expanding member 32 and asecond distal self-expanding member 33. As defined herein, the proximalend of the elongate shaft is the end 15 proximal to an operator of thedelivery system 10 during use. The distal end of the elongate shaft isthe end 16 that enters and extends into the patient's body. The proximaland distal directions for the delivery system 10 and endovascular graft11 loaded within the delivery system 10 as used herein are the same.This convention is used throughout the specification for the purposes ofclarity, although other conventions are commonly used. For example,another useful convention defines the proximal end of an endovasculargraft as that end of the graft that is proximal to the source of bloodflow going into the graft. Such a convention is used in the previouslydiscussed co-pending patent application, Ser. No. 09/133,978, althoughthat convention is not adopted herein.

[0076] The guidewire tube 17 has an inner lumen 34, as shown in FIG. 2,a distal section 35, a proximal end 36, as shown in FIG. 8, and a distalend 37. The inner lumen 34 of the guidewire tube 17 terminates at thedistal end 37 with a distal guidewire tube port 38, as shown in FIG. 10.As seen in FIG. 8, the proximal end 36 of guidewire tube 17 terminatesin a port 41 disposed in the proximal adapter 42. The port 41 istypically a tapered fitting such as a Luer lock fitting whichfacilitates the attachment of a hemostasis valve (not shown). Theguidewire tube 17 is a hollow tubular member that normally has anannular cross section, although oval cross-sectional profiles and othersare also suitable.

[0077] A portion of the distal section 35 of the guidewire tube 17,shown in FIG. 1, is disposed within an inner lumen 43 of a distal nosepiece 44, as shown in FIG. 5. Distal nose piece 44 is configured in astreamlined bullet shape for easy passage within a patient lumen orvessel such as aorta 45. Guidewire tube 17 may be bonded to the innerlumen 43 of the nose piece 44, or it may be molded into the nose piece44 during manufacture. Referring to FIG. 1, the nose piece 44 has adistal portion 46, an intermediate portion 47 and a proximal shoulderportion 48 configured to slidingly engage the distal portion 51 of aninner lumen 52 of an outer tubular member 53.

[0078] Referring to FIGS. 1, 6A, 6B and 7A, on the distal section 35 ofguidewire tube 17, proximal to the proximal shoulder portion 48 of nosepiece 44, a first distal belt 21 is secured to the guidewire tube 17.The first distal belt may be secured to the guidewire tube 17 with anysuitable adhesive such as cyanoacrylate, epoxy or the like. Both freeends 55 and 56 of the first distal belt 21 are secured to the guidewiretube 17. The guidewire tube 17 may be made from a variety of suitablematerials including polyethylene, teflon, polyimide and the like.

[0079] Referring to FIGS. 2-5, the inner lumen 34 of the guidewire tube17 has an inside diameter that can accommodate a guidewire suitable forguiding a device such as delivery system 10. The inner lumen 34 of theguidewire tube 17 may have an inside diameter of about 0.015 inch toabout 0.045 inch; specifically, about 0.020 inch to about 0.040 inch.The outer diameter of the guidewire tube 17 may range from about 0.020inch to about 0.060 inch; specifically, about 0.025 inch to about 0.045inch.

[0080] Referring again to FIGS. 6A, 6B and 7A, an optional first distalbelt bushing 57 is disposed about the guidewire tube 17 so as to coverthe portions of the free ends 55 and 56 of the first distal belt 21 thatare secured to the distal section 35 of the guidewire tube 17. Thisbushing 57 may also serve to control the constrained configuration ofthe belted self-expanding members, and may include geometric features toengage or support the belted members. A similar configuration is presentat a second distal belt 22 which has free ends secured to the guidewiretube 17 proximal to the first distal belt 21. A second distal beltbushing 63 is disposed about the guidewire tube 17 so as to cover theportions of the free ends of the second distal belt 22 that are securedto the guidewire tube 17. A proximal belt 23 has free ends secured tothe guidewire tube 17 proximal to the second distal belt 22 and has anoptional proximal belt bushing 67, as shown in FIG. 6, configuredsimilarly to the first and second distal belt bushings 57 and 63.

[0081] The belts 21, 22 and 23 can be made from any high strength,resilient material that can accommodate the tensile requirements of thebelt members and remain flexible after being set in a constrainingconfiguration. Typically, belts 21, 22 and 23 are made from solid ribbonor wire of a shape memory alloy such as nickel titanium or the like,although other metallic or polymeric materials are possible. Belts 21,22 and 23 may also be made of braided metal filaments or braided orsolid filaments of high strength synthetic fibers such as Dacron®,Spectra or the like. An outside transverse cross section of the belts21, 22 and 23 may range from about 0.002 to about 0.012 inch,specifically, about 0.004 to about 0.007 inch. The cross sections ofbelts 21, 22 and 23 may generally take on any shape, includingrectangular (in the case of a ribbon), circular, elliptical, square,etc.

[0082] In general, we have found that a ratio of a cross sectional areaof the belts to a cross sectional area of the release members, 24 and25, of about 1:2 is useful to balance the relative strength andstiffness requirements. Other ratios, however, may also be useddepending on the desired performance characteristics.

[0083] The inner diameters of belt bushings 57, 63 and 67 are sized tohave a close fit over the guidewire tube 17 and secured portion 71, asshown in FIG. 7A, of the free ends of the belts 21, 22 and 23 that aresecured to the guidewire tube 17. Typically, the inner diameter of thebelt bushings 57, 63 and 67 range from about 0.025 inch to about 0.065inch; specifically, about 0.030 inch to about 0.050 inch. In addition,the outer diameter of belt bushing 57 may be sized to approximate aninner diameter 70, as shown in FIG. 4, of the respective first distalself-expanding member 32 of the endovascular graft 11 when the member 32is in a fully constrained state. The other belt bushings 63 and 67 maybe similarly configured with respect to the second distal self-expandingmember 33 and the proximal self-expanding member 31.

[0084] Such an arrangement keeps the self-expanding members 31, 32 and33 properly situated when in a constrained state and prevents thevarious portions of the self-expanding members 31, 32 and 33 fromoverlapping or otherwise entangling portions thereof while in aconstrained state. The outer diameter of the belt bushings 57, 63 and 67may range from about 0.040 inch to about 0.200 inch; specifically, about0.060 inch to about 0.090 inch. The material of the belt bushings 57, 63and 67 may be any suitable polymer, metal, alloy or the like that isbondable. Generally, the belt bushings 57, 63 and 67 are made from apolymer such as polyurethane, silicone rubber or PVC plastic.

[0085] As shown in FIG. 7A, belts 21, 22 and 23 extend radially from theguidewire tube 17 through optional standoff tubes 72, 73 and 74.Standoff tubes 72, 73 and 74 are disposed about belts 21-23 adjacent theguidewire tube 17 and act to prevent separation of belts 21-23 in acircumferential direction as tension is applied to the belts. Standofftubes 72-74 also prevent belts 21-23 from applying other undesirableforces on portions of the endovascular graft 11 that are constrained bythe belts. Specifically, the standoff tubes 72-74 prevent the belts21-23 from spreading the self-expanding members 31-33, or portionsthereof, at those locations where the belts 21-23 extend radiallythrough the self-expanding members.

[0086] The standoff tubes 72-74 typically have a length substantiallyequal to a single wall thickness of the self-expanding members 31, 32and 33. The length of the standoff tubes 72-74 may range from about0.010 inch to about 0.030 inch. An inner diameter of an inner lumen 75of the standoff tubes, as shown in FIG. 4, may range from about 0.004 toabout 0.024 inch, with a wall thickness of the standoff tubes beingabout 0.002 inch to about 0.006 inch. Typically, the standoff tubes72-74 are made from a high strength metal or alloy such as stainlesssteel, although they may be polymeric as well.

[0087] Belts 21-23 exit the outer apertures of standoff tubes 72-74 andextend circumferentially about the respective portions of the expandableintracorporeal device 11. The term “circumferential extension” as usedwith regard to extension of the belts 21-23 is meant to encompass anyextension of a belt in a circumferential direction. The belts may extendcircumferentially a full 360 degrees, or any portion thereof. Forexample, belts or belt segments may extend partially about anendovascular device, and may be combined with other belts or beltsegments that also partially extend circumferentially about anendovascular device. Typically, a plane formed by each of the belts21-23 when in a constraining configuration is generally perpendicular toa longitudinal axis 76, shown in FIG. 1, of the distal section 14 ofshaft 12. As shown in FIGS. 6A and 6B, loop ends 81, 82 and 83 of thebelts 21, 22 and 23, respectively, are releasably locked together by oneor more release members. For example, in the embodiment shown in FIG. 1,a release member in the form of a first release wire 24 is showndisposed within end loops 81 of the first distal belt 21 and end loops82 of the second distal belt 22 so as to secure the first and seconddistal belts 21 and 22 in a constraining configuration about theendovascular graft 11. Another release member in the form of a secondrelease wire 25 is shown disposed within end loops 83 of the proximalbelt 23 so as to secure the proximal belt 23 in a constrainingconfiguration about the endovascular graft 11.

[0088] A single release wire may also be used to perform the function ofeach of the first and second release wires, 24 and 25, so that firstdistal belt 21, second distal belt 22, and proximal belt 23 may bereleasably secured by a single release wire. A highly controlled,sequential belt deployment scheme may be realized with the use of asingle release wire.

[0089] Any number of release wires and belts as may be needed toeffectively secure and deploy graft 11, in combination, are within thescope of the present invention.

[0090] In some embodiments of the invention, when constrained, the endloops of any single belt touch each other or are spaced closely togethersuch that the belt as a whole forms a substantially circular constraintlying substantially in a plane. Release wire 24 and 25 may be made fromsuitable high strength materials such as a metal or alloy (e.g.,stainless steel) which can accommodate the torque force applied to therelease wire by the belt end loops 83 when the belts 23 are undertension from the outward radial force of the constrained portions of theendovascular graft 11, i.e., the self-expanding members 32 and 33.

[0091] The release wires 24 and 25 may generally have an outer diameterranging from about 0.006 to about 0.014 inch. Distal end portions 84 and85 of release wires 24 and 25, respectively, may terminate at anyappropriate site distal of the end loops 81-83 of belts 21-23. As shownin FIG. 8, the proximal ends 86 and 87 of the release wires 24 and 25extend through the elongate shaft 12 of the delivery system 10 throughproximal ports 91 and 92 on the proximal adapter 42, respectively, andterminate at respective release wire handles 93 and 94 which arereleasably secured to the proximal adapter 42.

[0092]FIG. 7B illustrates an alternative embodiment of the belts 21-23of FIG. 7A. In FIG. 7A, belts 21-23 are shown as each consisting of asingle strand of wire formed into the end loops 81-83, respectively,with the end loops in an overlapping configuration. Free ends 55 and 56of belt 81 are shown secured to the distal section 35 of the guidewiretube 17. In contrast, FIG. 7B, wherein like elements with regard to FIG.7A are shown with like reference numerals, shows belts 21B, 22B and 23Bformed of two strands of wire, with each strand formed into a singleloop which overlaps a loop of the other strand to form end loops 81B,82B and 83B. The free ends of the belts 21B-23B may be secured in asimilar manner to those of free ends 55 and 56 of FIG. 7A.

[0093] Turning now to FIGS. 7C and 7D, alternative embodiments forportions of the delivery system of the present invention are shown.FIGS. 7C and 7D illustrate alternative belts 21C, 22C and 23C disposedon guidewire tube 17. Single or multiple belts 21C-23C may be deployedat various locations along guidewire tube 17 as desired. In addition,the members comprising belts 21C-23C are shown as a single line.However, belts 21C-23C may be of a single- or multiple strand orfilament design with various cross-sectional shapes as previouslydescribed. A single solid ribbon or wire is particularly useful.

[0094] Belts 21C-23C shown in FIGS. 7C and 7D are a single strandfilament wrapped around guidewire tube 17 and fixed thereon via anynumber of suitable techniques, such as gluing with adhesive, mechanicalfixation, etc. Especially useful is fixing the belt with anultraviolet-curable adhesive.

[0095] Alternatively, belts 21C-23C may comprise two strand filamentseach wrapped around guidewire tube 17 so that, for instance, belt 21C isa two-filament component.

[0096] Belt 21C includes belt arms 112 and 114, each of which, in theembodiments shown, is a loop of filament twisted upon itself to form ahelix. Any number of twists may be imparted to arms 112 and 114 toprovide a relatively loose or relatively tight helix as desired.Typically the number of twists (with a single twist being defined as asingle overlap of wire segment) in each belt arm 112 and 114 numbersfrom zero to about 50 or more; specifically, about two to about 10. Thechoice of material used for belt 21C is an important factor indetermining the optimum number of twists for each belt arm. Belt arms112 and 114 may be formed into other configurations (e.g., braid, doublehelix, etc.) as well.

[0097] Disposed within the end loops of the belt arms 112 and 114 aredistal apertures or openings 120, 122, respectively. During assembly ofthe delivery system, a release wire (such as wire 24) is passed througheach aperture 120, 122 after the belt arms are wrapped around the graftself-expanding member, preferably in a circumferential groove as furtherdescribed below. The release wire may also be disposed through anyaperture created along the length of belt arms 112, 114 by each helixtwist, although the distal-most apertures 120, 122 are preferred.

[0098] The wire optionally may be welded, glued, or otherwise fixed toitself at discrete points or along all or any portion of belt arms 112,114, save their corresponding apertures 120 and 122. For instance, thebelt arm wire may be glued or welded to itself at the overlap or twistpoints, such as points 124.

[0099]FIG. 7D shows an optional belt arm sleeve 126 that may be used toenclose a portion of one or both belt arms 112, 114, or any of the otherbelt embodiments contemplated herein. Belt 112 is shown in FIG. 7D beingconstrained or covered over a length thereof by a flexible sleeve orcoating 126 (or alternatively, a coil wrapping or by fixing the loop toitself by adhesives, welding, soldering, brazing, etc.). Sleeve orcoating 126 may optionally be shrink-wrapped, crimped, or otherwiseconfigured to constrain or cover belt arm 112 therein. These fixationand sleeve features help to minimize the potential of belt armuntwisting and tend to close or block some or all of the helix aperturesalong the length except those through which the release wire areintended to pass. They can also provide greater structural andoperational stability to the catheter system as a whole.

[0100] Belt arm sleeve 126 can be configured to have a transversedimension that is sized to fit a twisted belt arm with fixed nodalpoints such as the belt arm 112 shown in FIG. 7D. In order toaccommodate such a twisted belt arm 112, the inner diameter and outerdiameter would be large relative to a transverse dimension of the wirematerial that forms the belt arm 112. However, the belt arm sleeve 126can also be only slightly larger in transverse dimension that the wirethat forms the belt arm. For example, embodiments of belt arms that donot have twisted wires may have a sleeve 126 that fits closely ortightly over two strands of wire forming a belt arm. The sleeve 126 cancover substantially the entire length of such an untwisted belt arm fromat least the guidewire tube to just proximal of the distal loop, such asdistal loop 120. The distal loop should remain exposed for engagement bya release wire. In such an embodiment, the sleeve covered portion of thebelt arm may also be wrapped around and secured to the guidewire tubejust as the unsleeved belt portion of the belt arm 112 shown in FIG. 7Dis shown at 71C. This type of low profile belt arm sleeve may also beused to cover twisted belt arm embodiments, although a slightly largerdiameter sleeve would be required.

[0101] It may be desirable to impart a particular free resting angle tothe belt arms 112, 114 to improve the reliability of the system andfurther reduce the possibility of the arms 112 and 114 interfering withother components of the prosthesis or delivery system. The FIG. 7C viewshows belt arms 112, 114 symmetrically disposed at an angle α asmeasured from a horizontal plane 125. This angle α may range from zeroto 180 degrees. For example, one or both belt arm 112, 114 may lie alongplane 125 or they may rest in the configuration shown (α=45 degrees).Any known techniques may be used to impart a desired restingconfiguration to the system, such as, for example, cold working orshape-setting by way of an athermal phase transformation (in the case ofshape memory alloys).

[0102]FIG. 7J shows a single belt example of the version shown in FIGS.7C and 7D. Here, a single belt arm 113 is shown disposed about thedistal end 35 of guidewire tube 17. Belt arm 113 is significantly longerthan either belt arm 112 or 114 of the FIGS. 7C-7D embodiment so that itmay extend at least around the circumference of any one of self10expanding members 31, 32, or 33. The distal portion 115 of belt arm 113meets a more proximal portion 117 where one or both strands (when thebelt arm 113 is a twisted variety) extends through an end loop 119 inthe belt arm 115 distal portion. As discussed with other embodiments, arelease member such as release wire 24 may be inserted through end loop119 and the intersecting portion of the belt arm proximal portion 117 toreleasably secure belt arm 113 in a constraining configuration about theendovascular graft 11. FIG. 7K depicts a simplified schematiccross-sectional view of belt arm 113 (shown here untwisted) held inplace by a release wire 24 about an exemplary self-expanding member 32.FIG. 7L is a detail of the connection formed where release wire 24intersects the distal and proximal portions, 115 and 117, respectively,of belt arm 113.

[0103] All of the features discussed herein with respect to the FIGS.7C-7D embodiment may be employed in the embodiment of FIGS. 7J-7K aswell.

[0104] This helix configuration shown in the embodiments of FIGS. 7C-7Dand 7J-7L is a particularly reliable configuration. It reduces thepossibility that a portion of belt 21C becomes entangled with aself-expanding member (such as members 31, 32 and 33) or otherwiseinterferes with the safe and effective deployment of the prosthesis.

[0105]FIG. 7E depicts a particularly useful arrangement for configuringthe belt end loops 81-83 with release wires 24-25 during assembly ofdelivery system 10. In this example, first and second end loops 81′ and81″ of belt 21 are shown connected via release wire 24. To achieve theconfiguration of FIG. 7E, first end loop 81′ is passed through aperture88 disposed in second end loop 81″. A portion of aperture 89 disposed infirst end loop 81′ should extend through the plane created by second endloop 81″ as shown in FIG. 7E.

[0106] Next, release wire 24 is passed through the portion of aperture89 that extends beyond this plane so that wire 24 “locks” the two loopedends 81′ and 81″ together as shown. We have found that this is a stableconfiguration that lends itself well to a reliable and safe deploymentprotocol.

[0107] Other techniques for assembling wire 24 and first and second endloops 81′ and 81″ may be used; the method described above is merelyexemplary. Wire 24 may simply pass through loop ends as configured andas shown at reference numerals 81, 82 and 83 in FIG. 7A, and 81B, 82Band 83B of FIG. 7B as well.

[0108] In the embodiment of FIG. 7F, belt 110 is a member in the shapeof a wire formed into an end loop 116B having an aperture 120 forreceiving a release wire. This arrangement may be used on one or bothends of belt 110 or, alone if belt 110 is in the form of a single beltarm as discussed above. Connection 123 is shown in FIG. 7F as a simplewrapping of the distal end 116A of the wire comprising belt 110.Connection 123 need not be limited to such a tapered or cylindricalsleeve or coating, however. Other methods to form end loop 116B arecontemplated, including, for example, the use of adhesives, welding,brazing, soldering, crimping, etc. An optional protective sleeve orcoating 127 (shown in sectional view in FIG. 7F) covers or is part ofconnection 123 and serves to protect the patient as well as componentsof the delivery system and prosthesis from damage.

[0109] Turning now to FIGS. 7G and 7H, two alternative embodiments of aribbon-like belt 81G and 81H are shown. In FIG. 7G, a section 128 ofmaterial has been partially displaced from belt 81G distal end 116C andworked into a loop-like member 129 such that two generally orthogonalapertures 130, 132 are formed in belt distal end 116C. A set of hingesor other protective mechanism or material may be used on each end ofthis member 128 so that further tearing or peeling of this member may beprevented. Section 128 may be formed integrally from the belt distal end116C as shown in FIG. 7G or may be a separate component that is attachedto the belt distal end by any suitable means.

[0110] Second belt distal end 118C in FIG. 7G is shown as having anaperture 133 disposed therein. In use, a half-twist is imparted to theribbon-like belt 81G as the second distal end 118C is brought throughaperture 130 such that apertures 132 and 133 are at least partiallyaligned. A release wire (such as wire 24) is then brought throughapertures 132 and 133 to releasably join ends 116C and 118C.

[0111]FIG. 7H shows yet another embodiment of a belt 81H where a simplerectangular aperture 133A is disposed in the distal end 117 of belt 81Hthrough which another belt end and release wire may be disposed astaught herein. As with the embodiment of FIG. 7G, a half-twist isimparted to the belt 81H in use so that the second distal end 118D isbrought through aperture 133. A release wire may then be threadedthrough apertures 132 and 133 to releasably join ends 117 and 118D. Inthis embodiment, aperture 132 should be large enough to accommodate bothsecond distal end 118D and a release wire.

[0112]FIG. 7I shows a perspective view of a belt assembly similar tothat shown in FIG. 7A, wherein like elements are shown with likereference numerals. An alternative embodiment of a release wireconsisting of a branched release wire 150 is illustrated in FIG. 71. Thebranched release wire 150 engages belts 21-23 and is configured torelease belts 21-23 at different times with a proximal withdrawalmovement of the branched release wire 150, the direction of which isindicated by arrow 151. Branched release wire 150 has a main portion 152and a branch portion 153. Branch portion 153 is secured to main portion152 by a solder joint 154. The joint 154 could also be made by any othersuitable means, such as welding, bonding with an epoxy, mechanicallybinding the joint, or the like. The embodiment of the branched releasewire shown in FIG. 7I consists of wire which is generally round in crosssection. The wire of the branched release wire can have the same orsimilar material and mechanical properties to the wire of the releasewires 24 and 25 discussed above. Branch portion 153 engages first distalbelt 21 and second distal belt 22. A distal segment 155 has a length Lindicated by arrow 156 which extends distally from first distal belt 21to the distal end 157 of branch portion 153.

[0113] Main portion 152 of the branched release wire 150 engages theproximal belt 23 and has a distal segment 158 that extends distally fromthe proximal belt 23 to a distal end 161 of the main portion. The lengthL′ of the distal segment 158 of the main portion 152 is indicated byarrow 162. Length L of distal segment 155 is greater than length L′ ofdistal segment 158. In this way, as the branched release wire iswithdrawn proximally, proximal belt 23 is released first, first distalbelt 21 is released second and second distal belt is released last. Sucha branched release wire allows a wide variety of belt release timingwith a single continuous withdrawal or movement of a proximal end (notshown) of the branched release wire 150. The proximal end of thebranched release wire may be terminated and secured to a release wirehandle or the like, as discussed herein with regard to other embodimentsof release wires. The ability to deploy multiple release wires in adesired timing sequence with a single branched release wire 150 givesthe designer of the delivery system great flexibility and control overthe deployment sequence while making the deployment of the belts simpleand reliable for the operator of the delivery system. Although thebranched release wire 150 has been shown with only a single branch, anynumber of branches or desired configuration could be used to achieve thedeployment sequence required for a given embodiment of a deliverysystem. For example, a separate branch could be used for each belt in amultiple belt system, with varying distal segment length used to controlthe sequence of deployment. Also, multiple branched release wires, orthe like, could be used in a single delivery system to achieve thedesired results.

[0114] A number of embodiments for the belt and belt arm components ofthe present invention are described herein. In general, however, wecontemplate any belt or belt arm configuration in which the belt may beused to releasably hold or restrain an implant member in conjunctionwith a release member. The particular embodiments disclosed herein arenot meant to be limiting, and other variations not explicitly disclosedherein, such as those in which multiple apertures (which may havevarying shapes and sizes) are disposed along the belt length, those inwhich the belt or belt arm distal ends comprises a separate material orelement that is affixed to the belt or belt arm, etc. are within thescope of the invention. Furthermore, various embodiments of the ends ofthe belts or belt arms taught herein may exist in any combination in asingle delivery system.

[0115] Turning now to FIG. 6A, belts 21-23 lie within circumferentialgrooves or channels 95, 96 and 97, respectively, formed into therespective self-expanding members 31, 32 and 33. Grooves 95-97 preventaxial displacement of the belts 21-23 prior to activation or release ofthe releasable members 24 and 25, i.e., proximal retraction of the firstand second release wires. Although grooves 95-97 are illustrated in theembodiment shown, other alternatives are possible to achieve the same orsimilar function of the grooves. For example, abutments extendingslightly from the self-expanding members 31-33 on either side of thebelts 21-23 in their constraining configuration could prevent axialmovement of the belts. A detachable adhesive or the like could also beused.

[0116] As shown in FIG. 10, the release of end loops 81-83 occurs whenthe distal end portions 84 and 85 of the release wires 24 and 25,respectively, pass from within the overlapped end loops 81-83. If theend loops 81-83 move axially in response to movement of the releasewires 24 and 25 due to frictional forces imposed on the end loops 81-83by the release wires, the point at which the distal ends of the releasewires 84 and 85 pass from within the end loops 81-83 would varydepending on the amount of movement of the end loops 81-83.

[0117] If the end loops 81-83 were to be axially displaced from theirnormal position relative to the distal ends of the release wires priorto deployment, the timing of the release of the belts 21-23 could beadversely affected. Thus, the prevention of axial displacement of thebelts 21-23 during proximal retraction of the release wires 24 and 25facilitates accurate release of the belts by keeping the overlap jointof the belt looped end portions in a constant axial position during suchretraction.

[0118] In addition, it may be desirable to keep belts 21-23 positionedat or near the general center of a given constrained self-expandingmembers 31-33 so that the self-expanding member 31-33 is substantiallyuniformly and evenly constrained over its axial length. If belts 21-23constrain the self-expanding members 31-33 at a non-centered axialposition on the member, an end of the member opposite that of thenon-centered position may be less constrained and may interfere withaxial movement of the outer tubular member 53 (and consequentlydeployment of the endovascular graft 11).

[0119] Tubular body member 205 of the endovascular graft 11 is disposedbetween and secured to the second distal self-expanding member 33 andthe proximal self-expanding member 31. The tubular body member comprisedof flexible material 204, is shown constrained in an idealized view inFIGS. 1, 3 and 6, for clarity. In practice, tubular body member 205while constrained is tightly compressed with minimal air space betweenlayers of flexible material 204 so as to form a tightly packedconfiguration as shown in FIG. 3. Tubular body member 205 is optionallyradially constrained by an inside surface 206 of the inner lumen 52 ofouter tubular member 53.

[0120] An inner tubular member 207 is slidably disposed within the innerlumen 52 of outer tubular member 53. Release wires 24 and 25, guidewiretube 17 and an inflation tube 211 are disposed within an inner lumen 212of the inner tubular member 207. Inner lumen 212 is optionally sealedwith a sealing compound, depicted in FIGS. 1, 2 and 6 by referencenumeral 213 at distal end 214. The sealing compound 213 prevents leakageof fluids such as blood, etc., from a proximal end 215, shown in FIG. 8,of the inner tubular member 207. Sealing compound 213 fills the spacewithin the inner lumen 212 of the inner tubular member 207 between anouter surface 216 of the guidewire tube 17, the outer surface 217 of theinflation tube 211 and outer surfaces 221 and 222 of a tubular guide 223for the first release wire 24 and a tubular guide 224 for the secondrelease wire 25. The sealing compound 213 can be any suitable material,including epoxies, silicone sealer, ultraviolet cured polymers, or thelike.

[0121] In FIG. 2, the tubular guides 223 and 224 for the first releasewire 24 and the second release wire 25 allow axial movement of therelease wires with respect to the sealing compound 213 and inner tubularmember 207. The inside diameter of the inner lumens of the tubularguides 223 and 224 are sized to fit closely with an outer diameter ortransverse dimension of the release wires 24 and 25. Alternatively,tubular guides 223 and 224 may be replaced by a single tubular guidethat houses one or more release wires, such as wires 24 and 25.

[0122] Turning to FIG. 8, the inner tubular member 207 terminatesproximally with the proximal adapter 42 having a plurality of side arms225, 226 and 227 and a proximal exit port 231 for the inner lumen 34 ofthe guidewire tube 17. First release wire side arm 225 branches from aproximal adapter body portion 233 and has an inner lumen 234 andproximal end 86 of the first release wire 24. A proximal extremity 236of the first release wire 24 is anchored to the first release wireproximal handle 93 which is threaded onto the proximal end 238 of thefirst release wire side arm 225. The proximal extremity 236 of firstrelease wire 24 is configured as an expanded bushing or other abutmentthat captures the handle 93 and translates proximal axial movement ofthe handle 93 to the first release wire 24 but allows relativerotational movement between the handle 93 and the proximal end 86 of thefirst release wire 24.

[0123] A similar configuration exists for the proximal end 87 of thesecond release wire 25. There, a second release wire side arm 226branches from the proximal adapter body portion 233 and has an innerlumen 244 that houses the proximal end 87 of the second release wire 25which is free to slide in an axial orientation within the lumen 244. Aproximal extremity 246 of the second release wire 25 is configured as anexpanded bushing or other abutment that captures the second release wirehandle and translates axial proximal movement of the second release wirehandle 94 to the second release wire 25, but allows relative rotationalmovement between the proximal end 87 of the second release wire 25 andthe second release wire handle 94.

[0124] The first release wire handle 93 and second release wire handle94 may optionally be color coded by making each, or at least two,release wire handles a color that is distinctly different from theother. For example, the first release wire handle 93 could be made greenin color with the second release wire handle 94 being red in color. Thisconfiguration allows the operator to quickly distinguish between the tworelease wire handles and facilitates deployment of the belts in thedesired order.

[0125] In another embodiment, instead of color coding of the releasewire handles 93 and 94, the spatial location of the handles can beconfigured to convey the proper order of deployment of the release wiresto the operator of the delivery system. For example, if three releasewire handles are required for a particular embodiment, the correspondingthree side arms can be positioned along one side of the proximaladapter. In this configuration, the release wire handle that needs to bedeployed first can extend from the distal-most side arm. The releasewire handle that needs to be deployed second can extend from the middleside arm. The release wire handle that is to be deployed last can extendfrom the proximal-most side arm. For such a configuration, the operatoris merely instructed to start deployment of the release wires at thedistal-most release wire handle and work backward in a proximaldirection to each adjacent release wire handle until all are deployed.Of course, an opposite or any other suitable configuration could beadopted. The configuration should adopt some type of spatially lineardeployment order, either from distal to proximal or proximal to distal,in order to make reliable deployment of the release wires in the properorder easy to understand and repeat for the operator of the deliverysystem. Other types of release order indicators such as those discussedabove could also be used, such as numbering each release wire handle orside arm with a number that indicates the order in which that handle isto be deployed.

[0126] The proximal end 36 of the guidewire tube 17 terminates and issecured to an inner lumen 251 of the proximal end 259 of the proximaladapter 42. Inner lumen 251 typically has a longitudinal axis 253 thatis aligned with a longitudinal axis 254 of the proximal section 13elongate shaft 12 so as to allow a guidewire to exit the proximal end 15of the elongate shaft 12 without undergoing bending which could createfrictional resistance to axial movement of the guidewire. A proximalport 255 of the proximal adapter 42 may be directly fitted with ahemostasis valve, or it may be fitted with a Luer lock fitting which canaccept a hemostasis valve or the like (not shown).

[0127] The proximal adapter 42 may be secured to the proximal end 215 ofthe inner tubular member 207 by adhesive bonding or other suitablemethod. A strain relief member 256 is secured to the distal end 257 ofthe proximal adapter 42 and the inner tubular member 207 to preventkinking or distortion of the inner tubular member 207 at the joint.

[0128] As seen in FIG. 1, the proximal end 261 of the outer tubularmember 53 is secured to a proximal fitting 262 that slides over an outersurface 258 of the inner tubular member 207. A seal 263 located inproximal fitting 262 provides a fluid seal for the lumen 265 formedbetween the outer surface 258 of the inner tubular member 207 and theinner surface 206 of the inner lumen 52 of the outer tubular member 53.The fit between the outer surface 258 of the inner tubular member 207and the inner surface 206 of the outer tubular member 53 is typicallyclose, but still allows for easy relative axial movement between outertubular member 53 and inner tubular member 207. A stop 266 is disposedand secured to the outer surface 258 of the inner tubular member 207distal of the proximal adapter 42 to limit the amount of proximal axialmovement of the outer tubular member 53 relative to the inner tubularmember 207.

[0129] When the outer tubular member 53 is positioned on the proximalshoulder 48 of the distal nose piece 44 prior to deployment ofendovascular graft 11, the distance between a proximal extremity 267 ofproximal fitting 262 and a distal extremity 268 of stop 266 isapproximately equal to or slightly greater than an axial length of theendovascular graft 11 in a constrained state. This configuration allowsthe outer tubular member 53 to be proximally retracted to fully exposethe endovascular graft 11 in a constrained state prior to deployment ofthe graft. This distance may be greater, but should not be less than thelength of the endovascular graft 11 in a constrained state in order tocompletely free the constrained graft 11 for radial expansion anddeployment.

[0130] Retraction limiters may alternatively be used to preventexcessive axial movement of the release wires 24 and 25 in a proximaldirection during deployment. Particularly in embodiments of theinvention where single release wires are used to constrain and deploymultiple belts such as with first release wire 24, retraction limitersmay be used to allow enough axial movement of the release wire 24 todeploy a first belt 21, but prevent deployment of a second moreproximally located belt 22. For example, as shown in FIG. 8, aretraction limiter in the form of a filament 268 could be disposedbetween the proximal adapter 42 and the handle 93 of the first releasewire 24 such that proximal retraction of the first release wire 24sufficient for deployment of the first distal belt 21 could be achieved,but not so much as to allow deployment of the second distal belt 22. Inorder to deploy the second distal belt 22, the filament 268 would haveto be severed or otherwise released. This type of configuration canallow more control over deployment of the endovascular graft 11 andallow deployment in stages which are sequentially controlled to preventinadvertent deployment of a portion of the graft 11 in an undesirablelocation within the patient's vessels.

[0131] In use, the delivery system 10 is advanced into a patient'sarterial system 271 percutaneously as shown in FIG. 9 and positioned sothat the endovascular graft 11 spans an aneurysm 272 in the patient'saorta 45 as 20 illustrated in FIGS. 1 and 9-12. It is generallydesirable to have the tubular body portion 205 of the graft 11positioned below the renal arteries 273 in order to prevent significantocclusion of the renal arteries.

[0132] The procedure typically begins with the placement of guidewire 18into the patient's target vessel 45 across the target location, e.g.,the aneurysm 272. Common percutaneous techniques known in the art may beused for the initial placement of the guidewire 18. For example, asshown in FIG. 9, percutaneous access to the aorta may be had through thefemoral or iliac artery, although other access sites may be used. Thedelivery system 10 may then be advanced over the guidewire 18 to adesired position within the patient's vessel 45. Alternatively, deliverysystem 10 and guidewire 18 could be advanced together into the patient'svasculature 272 with the guidewire 18 extending distally from the distalport 38 of the guidewire tube 17. In addition, it may be desirable insome cases to advance the delivery system 10 to a desired locationwithin the patient without the use of a guidewire 18. Generally, theposition of the delivery system 10 is determined using fluoroscopicimaging or the like. As such, it may be desirable to have one or moreradiopaque markers (not shown) secured to the delivery system at variouslocations. For example, markers may be placed longitudinally coextensivewith the respective distal and proximal extremities 274 and 275, asshown in FIG. 11. In this way, it can be readily determined whether thegraft 11 is spanning the aneurysm 272 of the patient's artery. Imagingmarkers, such as radiopaque markers, may also be secured to desirablepositions on the endovascular graft 11 itself. Other types of imagingand marking systems may be used such as computed tomography (CT),magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR)imaging systems and markers.

[0133] Once the distal section 14 of the delivery system 10 is properlypositioned within the patient's artery 45, the operator moves theproximal end 261 of outer tubular member 53 in a proximal directionrelative to inner tubular member 207. The relative axial movement iscarried out by grasping the proximal end 215 of the inner tubular member207 or proximal adapter 42, and grasping the proximal end 261 of theouter tubular member 53, and moving the respective proximal ends towardseach other. This retracts the distal section 276 of the outer tubularmember 53 from the constrained endovascular graft 11 and frees the graftfor outward radial expansion and deployment. However, in this deploymentscheme, note that the operator is free to reinsert graft 11 back intothe outer tubular member 53 if necessary, as the release bands have notyet released the graft.

[0134] Once the distal section 276 of the outer tubular member 53 hasbeen retracted, handle 93 of the first release wire 24 may then beunscrewed or otherwise freed from the proximal adapter 42 and retractedin a proximal direction indicated by arrow 279 in FIG. 10 until thedistal end 84 of the first release wire 24 passes from within the endloops 81 of the first distal belt 21. When this occurs, the looped ends81 of the first distal belt 21 are released and the first distal belt 21ceases to radially constrain the first distal self-expanding member 32which thereafter self-expands in a radial direction into an innersurface 278 of the patient's aorta 45 as shown in FIG. 10.

[0135] If the operator of the delivery system 10 is not satisfied withthe position, particularly the axial position, of the endovascular graft11 after deployment of the first distal self-expanding member 32, it maythen be possible to re-position the endovascular graft 11 bymanipulating the proximal end 15 of the elongate shaft 15. Movement ofthe elongate shaft 12 can move the endovascular graft 11, even thoughphysical contact between the expanded member 32 and the vessel innersurface 278 generates some static frictional forces that resist suchmovement. It has been found that the endovascular graft 11 can be safelymoved within a blood vessel 45 even in the state of partial deploymentdiscussed above, if necessary.

[0136] Once the operator is satisfied with the position of the graft 11,the first release wire 24 may then be further proximally retracted so asto deploy the second distal belt 22 in a manner similar to thedeployment of the first distal belt 21. The deployment of the seconddistal belt 22 occurs when the distal end 84 of the first release wire24 passes from within end loops 82 of the second distal belt 22 whichare held in a radially constraining configuration by the first releasewire 24. Upon release of the second distal belt 22, the second distalself-expanding member 33 expands in a radial direction such that it mayengage inner surface 278 of the patient's aorta 45. The amount ofoutward radial force exerted by the self-expanding members 32 and 33 onthe inside surface 278 of the patient's aorta 45, which may vary betweenmembers 32 and 33, is dependent upon a number of parameters such as thethickness of the material which comprises the self-expanding members 32and 33, the nominal diameter which the self-expanding members 32 and 33would assume in a free unconstrained state with no inward radial forceapplied, material properties of the members and other factors as well.

[0137] Once the distal members 32 and 33 are deployed, the handle 94 forthe second release wire 25 can be disengaged and axially retracted in aproximal direction from the proximal adapter 42 until the distal end 85of the second release wire 25 passes from within the end loops 83 of theproximal belt 23. Once the proximal belt 23 is released, the proximalself-expanding member 31 is deployed and expands in an outward radialdirection, such that it may engage or be in apposition with the innersurface 278 of the patient's aorta 45 as shown in FIG. 11. Thereafter,the endovascular graft 11 may be inflated with an inflation material(not shown) introduced into the proximal injection port 282 in theproximal adapter 42, through the inflation tube 211, and into theinflation port 283 of the endovascular graft 11. Inflation material maybe injected or introduced into the inflation port 283 until the proximaland distal inflatable cuffs 28 and 30 and inflatable channels 284 of thegraft 11 have been filled to a sufficient level to meet sealing andother structural requirements necessary for the tubular body to meetclinical performance criteria.

[0138] Before or during the deployment process, and preferably prior toor simultaneous with the step of inflating the endovascular graft 11, itmay be beneficial to optionally treat vessel 45 in which the graft 11 isdeployed so to obtain a better seal between the graft 11 and the vesselinner surface 278, thus improving the clinical result and helping toensure a long term cure.

[0139] One approach to this treatment is to administer a vasodilator, orspasmolytic, to the patient prior to deploying graft 11. This has theeffect of reducing the tone of the smooth muscle tissue in the patient'sarteries; specifically, the smooth muscle tissue in the wall of vessel45 into which graft 11 is to be deployed. Such tone reduction in turninduces the dilation of vessel 45, reducing the patient's bloodpressure. Any number of appropriate vasoactive antagonists, includingthe direct acting organic nitrates (e.g., nitroglycerin, isosorbidedinitrate, nitroprusside), calcium channel blocking agents (e.g.,nifedipine), angiotensin-converting enzyme inhibitors (e.g., captopril),alphaadrenergic blockers (e.g., phenoxybenzamine, phentolamine,prasozin), beta-adrenergic blockers (e.g., esmolol) and other drugs maybe used as appropriate. Particularly useful are those vasodilators thatcan be administered intravenously and that do not have unacceptablecontraindications such as aoritic aneurysm dissection, tachycardia,arrhythmia, etc.

[0140] The degree of vasodilatation and hypotensive effect will dependin part on the particular vessel in which graft 11 is to be placed andthe amount of smooth muscle cell content. Generally, the smaller thevessel, the larger percentage of smooth muscle cell present and thus thelarger effect the vasodilator will have in dilating the vessel. Otherfactors that will effect the degree of vasodilatation is the health ofthe patient; in particular, the condition of the vessel 11 into whichgraft 11 is to be placed.

[0141] In practice, once the vasodilator has been administered to thepatient, graft 11 may be deployed and filled with inflation material sothat graft 11 reaches a larger diameter than would otherwise be possibleif such a vasodilator was not used. This allows the inflation materialto expand the diameter of graft 11, for a given inflation pressure,beyond that which would be achievable if the vessel 45 were in anon-dilated state (and nominal diameter). Alternatively, a largerdiameter graft 11 may be chosen for deployment. We anticipate that anincreased vessel diameter of between two and twenty percent duringvasodilatation may be optimal for achieving an improved seal.

[0142] The vessel 45 in which graft 11 is to be placed may optionally bemonitored pre- and/or post-dilation but before deployment of graft 11(via computed tomography, magnetic resonance, intravenous ultrasound,angiography, blood pressure, etc.) so to measure the degree ofvasodilatation or simply to confirm that the vasodilator has acted onthe vessel 45 prior to deploying graft 11.

[0143] Once the vasodilator wears off, preferably after between aboutfive and thirty minutes from the time the drug is administered, thevessel 45 surrounding graft 11 returns to its normal diameter. Theresultant graft-vessel configuration now contains an enhanced sealbetween graft 11 and vessel inner surface 278 and provides for reducedluminal intrusion by graft 11, presenting an improved barrier againstleakage and perigraft blood flow compared to that obtainable without thesue of vasodilators or the like.

[0144] Such vasodilating techniques may be used with all of theembodiments of the present invention, including the tubular graft 11 aswell as a bifurcated graft version of the expandable intracorporealdevice of the present invention as is discussed in detail below.

[0145] Once graft 11 is fully deployed, a restraining or retentiondevice, such as retention wire 285 that binds the distal end 286 of theinflation tube 111 to the inflation port 283, as shown in FIGS. 12 and13, is activated. The retention wire 185 is activated by pulling theproximal end of the wire in a proximal direction so as to disengage thedistal ends 293 and 294 from the holes 295 and 296. This eliminates theshear pin function of the distal ends 293 and 294 and allows the distalend 286 of the inflation tube 211 to be disengaged from the inflationport 283. The release wires 24 and 25 may then be fully retracted fromthe elongate shaft 12 in a proximal direction and the delivery system 10retracted in a proximal direction from the deployed endovascular graft11. The unconstrained distal belts 21-23 slip through the openings inthe expanded members 31, 32 and 33 as the delivery system 10 isretracted and are withdrawn through the inner passageway 287 of thedeployed graft 11. The distal nosepiece 44 is also withdrawn through theinner passageway 287 of the deployed graft 11 as the delivery system 10is withdrawn as shown in FIG. 10-12.

[0146]FIG. 13 illustrates the junction between the distal end 286 ofinflation tube 211 and inflation port 283. Typically, retention wire 285extends from the inflation port 283 proximally to the proximal end 15 ofdelivery system 10. In this way, an operator can disengage the distalend 286 of the inflation tube 211 from the inflation port 283 by pullingon the proximal end 283 of retention wire 285 from a proximal end 15 ofdelivery system 10. The retention wire 285 can be a small diameter wiremade from a material such as a polymer, stainless steel, nickeltitanium, or other alloy or metal; in a particular embodiment of theinvention, retention wire 285 may be a spring formed of a variety ofsuitable spring materials. Alternatively retention wire 285 may have abraided or stranded configuration.

[0147]FIG. 13 shows a single retention filament or wire 285 disposedwithin the lumen 291 of the inflation tube 211. The distal end 292 ofretention wire 285 may have one or more loops 293 and 294, respectively,disposed within one or more side holes disposed in the inflation port283 of the distal end 286 of the inflation tube 211. A number of sidehole configurations may be utilized. The embodiment of FIG. 13 has twosets of opposed side hole locations 295 and 296. The distal loops 293and 294 of the retention wire 285 act to interlock the side holes 295and 296 by creating a removable shear pin element which preventsrelative axial movement between the distal end 286 of the inflation tube211 and the inflation port 283. Alternate embodiments may includemultiple retention filaments or wires disposed within the lumen 291 ofthe inflation tube 211. An external sleeve (not shown) may be added overthis assembly to further secure the interface and prevent leakage ofinflation material through side holes 295 and 296. This sleeve isattached to inflation tube 211 and is received with it.

[0148] FIGS. 14-17 illustrate an alternative embodiment of the deliverysystem shown in FIG. 1. In FIGS. 14-17, like elements with respect tothe embodiment of FIG. 1 will be shown with like reference numeralswhere appropriate. The delivery system 300 has an outer tubular member53 and inner tubular member 207 at a distal section 303 of the deliverysystem 300. An endovascular graft 11 is disposed within the outertubular member in the distal section 303. An inflation tube 305, similarto that of the embodiment shown in FIG. 1 is coupled to an inflationport 283 of the endovascular graft 11. However, the inflation tube 305,having a proximal end 307 and a distal end 308, does not extend themajority of the length of the delivery system 300. Instead, the proximalend 307 of the inflation tube 305 terminates at a proximal end 311 ofthe potted section 213 as shown in FIGS. 14 -16.

[0149] Referring to FIG. 14 and 16, first release wire 312 having distalend 313 engages end loops 82 of second distal belt 22. The second distalbelt 22 is disposed about and constrains the second distalself-expanding member 33. A second release wire 316 having a distal end317 engages the end loops 81 of the first distal belt 21 and the endloops 83 of the proximal belt 23. The first distal belt 21 is disposedabout and constrains the first distal self-expanding member 32. Theproximal belt 23 is disposed about and constrains the proximalself-expanding member 31. A release wire tube 318, having a proximal end321, as shown in FIG. 17, and a distal end 322, shown in FIG. 16,extends from the potted section 213 of the distal section 303 of thedelivery system 300 to the proximal adapter 323 shown in FIG. 17. Therelease wire tube 318 has a lumen 324, as shown in FIG. 15, whichcontains the first release wire 312 and the second release wire 316.

[0150] The proximal adapter 323 has a first side arm 324 with an innerlumen 325 that secures the proximal end 321 of the release wire tube318. A threaded end cap 326 is secured to a proximal end 327 of thefirst side arm 324 and has a threaded portion 328. A second release wirehandle 331, having a distal threaded portion 332 and a proximal threadedportion 333, is threaded onto the threaded end cap 326. A proximal end334 of the second release wire 316 is secured to the second release wirehandle 331. A first release wire handle 335 has a threaded portion 336that is releasably threaded onto the proximal threaded portion 333 ofthe second release wire handle 331. A proximal end 337 of the firstrelease wire 312 is secured to the first release wire handle 335.

[0151] Once the outer tubular member 53 has been proximally retracted,belts 21-23 can be released. This configuration allows the operator ofthe delivery system 300 to first disengage and proximally retract thefirst release wire handle 335 so as to first release the second distalself-expanding member 33 without releasing or otherwise disturbing theconstrained state of the first distal self-expanding member 32 or theproximal self-expanding member 31. Once the second distal self-expandingmember 33 has been deployed or released, the endovascular graft 11 maybe axially moved or repositioned to allow the operator to adjust theposition of the graft 11 for final deployment.

[0152] This is advantageous, particularly in the treatment of abdominalaortic aneurysms, because it allows the physician to accurately placegraft 11 into position. In many cases, it is desirable for the physicianto place the graft 11 such that the distal end of the tubular bodyportion 205 of the graft is just below the renal arteries 273, shown inFIG. 9, to prevent occlusion of the renal arteries by the tubular bodyportion 205. If a self-expanding member, such as self-expanding member32 is radiopaque and the delivery procedure is performed usingfluoroscopic imaging, adjustment of the position of the graft afterrelease of self-expanding member is readily achievable. Becauseself-expanding member 32 is immediately adjacent the distal end of thetubular body portion 205 of the graft 11, the ability to visualize andreposition the self-expanding member 32 is particularly useful in orderto position the distal end of the tubular body portion 205 just belowthe renal arteries without occluding the renal arteries, if suchpositioning is indicated for the patient being treated.

[0153] Thereafter, the second release wire handle 331 may be unscrewedor otherwise released from the end cap 326 and proximally retracted soas to first release the first distal belt end loops 81 and then theproximal belt end loops 83. Of course, the position of the graft 11 maystill be adjustable even with both distal self-expanding members 32 and33 deployed, depending on the particular configuration of the graft 11and the self-expanding members 32 and 33. The release of the belts 21,22 and 23 is the same or similar to that of the belts of the embodimentof FIG. 1 and occurs when the distal end of the release wires 313 and317 which lock the end loops 81-83 together is proximally retracted pastthe end loops 81-83 of the belts 21-23 which are constrained.

[0154] Once the self-expanding members 31-33 of the endovascular graft11 have been deployed or released, and the graft 11 is in a desiredlocation, the graft 11 can then be inflated by injection of an inflationmaterial (not shown) into the injection port 338 on a second side arm341 of the proximal adapter 323. The inflation material is introduced orinjected directly into an inner lumen 212 of the inner tubular member207, as shown in FIG. 17, and travels distally between an inside surface342 of the inner tubular member 207, outside surface 343 of the releasewire tube 318 and outside surface 216 of the guidewire tube 17. Thisallows the inflation material, which can be highly viscous, to flowthrough the cross sectional area between the inside surface 342 of theinner tubular member 207 and the outside surfaces 216 and 343 of therelease wire tube 318 and guidewire tube 17. This cross sectional areais large relative to the cross sectional area of the inner lumen of theinflation tube 211 of the embodiment of FIG. 1. This results in morerapid flow of inflation material to the inflatable cuffs 28 and 30 andchannels 284 of the endovascular graft 11 and decreases inflation time.

[0155] Once the inflation material, which is travelling distally in thedelivery system 300 during inflation, reaches the potted portion 213 ofthe distal section 303 of the delivery system, it then enters and flowsthrough a lumen 344, as shown in FIG. 16, at the proximal end 307 of theinflation tube 305 and into the inflation port 283 of the graft 11. Uponinflation of the graft 11 with an inflation material, a release device,such as retention wire 285 can be retracted or otherwise activated so asto de-couple the inflation tube 305 from the inflation port 283 of theendovascular graft 11.

[0156] A proximal end 36 of the guidewire tube 17 is secured within acentral arm 345 of the proximal adapter 323 that has a potted section346. A seal 349 is disposed on a proximal end 347 of the central arm 345for sealing around the guidewire 18 and preventing a backflow of bloodaround the guidewire. A hemostasis adapter (not shown) can be coupled tothe proximal end 347 of the central arm 345 in order to introduce fluidsthrough the guidewire tube lumen 348, as shown in FIG. 15, around anoutside surface of the guidewire 18. The potted section 346 of thecentral arm 345 prevents any fluids injected through the hemostatisadapter from passing into the inflation material lumen 351 within theproximal adapter 323 or the inner tubular member 207.

[0157]FIG. 18 illustrates an alternative embodiment to the proximaladapters 42 and 323 used in the embodiments of the invention of FIG. 1and FIG. 14. In this embodiment, the proximal adapter 360 has a firstrelease wire handle 361 and a second release wire handle 362 which arein a nested configuration. The proximal end 334 of the second releasewire 316 is secured to the second release wire handle 362. The proximalend 337 of the first release wire 312 is secured to the first releasewire handle 361. This configuration prevents the operator frominadvertently deploying or activating the second release wire 316 priorto deployment or activation of the first release wire 312 which couldresult in an undesirable endovascular graft deployment sequence.

[0158] In use, the operator first unscrews or otherwise detaches athreaded portion 363 of the first release wire handle 361 from an outerthreaded portion 364 of a first side arm end cap 365 of a first side arm366. The first release wire handle 361 is then proximally retractedwhich releases the end loops 82 of the second distal belt 22 asdiscussed above with regard to the embodiment of the invention shown inFIG. 14.

[0159] Once the first release wire handle 361 is removed from the firstside arm end cap 365, the second release wire handle 362 is exposed andaccessible to the operator of the delivery system. A threaded portion367 of the second release wire handle 362 can then be unscrewed orotherwise detached from an inner threaded portion 368 of the first sidearm end cap 365. The second release wire handle 362 can then beretracted proximally so as to sequentially deploy the first distal belt21 and self-expanding member 32 and proximal belt 23 and proximalself-expanding member 31, respectively. The other functions and featuresof the proximal adapter 360 can be the same or similar to those of theproximal adapters 42 and 323 shown in FIG. 1 and FIG. 17 and discussedabove.

[0160] Optionally, this embodiment may comprise reverse or oppositelythreaded portions, 363 and 367 respectively, of the first and secondrelease wire handles 361 and 362. Thus, for instance, acounter-clockwise motion may be required to unthread threaded portion363 of the first release wire handle 361 from the outer threaded portion364, while a clockwise motion is in contrast required to unthreadthreaded portion 367 of the second release wire handle 367 from theinner threaded portion 368. This feature serves as a check on theoverzealous operator who might otherwise prematurely unscrew or detachthe threaded portion 367 of the second release wire handle 362 byunscrewing in the same direction as required to release the threadedportion 363 of the first release wire handle 361.

[0161] In another aspect of the invention, a delivery system 400 fordelivery and deployment of a bifurcated intracorporeal device,specifically, an embodiment of the invention directed to delivery anddeployment of a bifurcated endovascular graft or stent is contemplated.As with all the delivery systems disclosed herein, the delivery system400 for a bifurcated device is configured for delivery and deployment awide variety of intracorporeal devices. Although the focus of thespecific embodiments are directed to systems for delivery ofendovascular grafts or stent grafts, embodiments of the delivery systemsdisclosed herein can are also suitable for delivery of intravascularfilters, stents, including coronary stents, other types of shunts forintracorporeal channels, aneurysm or vessel occluding devices and thelike.

[0162] The structure, materials and dimensions of the delivery system400 for bifurcated devices can be the same or similar to the structure,materials and dimensions of the delivery systems discussed above. Inaddition, the structure, materials and dimensions of bifurcated graftscontemplated herein can have structure, materials and dimensions similarto those of grafts having a primarily tubular shape discussed above.

[0163] FIGS. 19-22 illustrate an embodiment of an expandableintracorporeal device in the form of a bifurcated stent-graft 401. Thisembodiment includes a main body portion 402 at a distal end 403 of thegraft 401 that has a generally tubular cross-sectional profile when thegraft takes on an expanded or deployed configuration. An ipsilateral leg404 and contralateral leg 405 (short leg), both having a substantiallytubular configuration when expanded or deployed, branch from the mainbody portion 402 at bifurcation 406 and extend in a proximal directionfrom the bifurcation 406. The ipsilateral leg 404 terminates proximallywith a proximal self-expanding member 407 and the contralateral leg 405terminates proximally with a proximal self-expanding member 408.

[0164] The main body portion 402 of the graft may have a transversedimension when in an expanded or deployed state ranging from about 10 mmto about 40 mm, specifically from about 15 mm to about 30 mm.

[0165] The legs 404 and 405 of the graft 401 may have a transversedimension when in an expanded or deployed state ranging from about 5 mmto about 16 mm, specifically from about 8 mm to about 14 mm. The mainbody portion 402 of the graft 401 may have a length ranging from about 2cm to about 12 cm, specifically from about 4 cm to about 8 cm.

[0166] A second distal self-expanding member 411 is disposed at a distalend 412 of the main body portion 402 of the graft 401 as with the graftembodiments previously discussed. Also, as with other endovascular graftembodiments discussed herein, the graft 401 may have inflatable channelsand inflatable cuffs that serve, among other functions, to providesupport for the graft 401 and the inflatable channels and cuffs can haveconfigurations which are the same or similar to those inflatablechannels and cuffs of other graft embodiments discussed herein, as wellas other configurations. A distal inflatable cuff 413 is disposed at thedistal end 412 of the main body portion 402. Proximal inflatable cuffs414 and 415 are disposed on a proximal end 416 of the ipsilateral leg404 and a proximal end 417 of the contralateral leg 405 respectively.Inflatable channels 418 are fluid tight conduits which connect theinflatable cuffs 413, 414 and 415. The inflatable channels 418 andinflatable cuffs 413 and 414 are inflatable through an inflation port421 that may be disposed at or near the proximal end 416 of theipsilateral leg 404. The inflation port 421 may also be disposed at ornear the proximal end 417 of the contralateral leg 405, or it may bedisposed on other portions of the device as necessary. Generally, thestructure and the materials used in the graft 401 (both the graftportion and the self-expanding members) can be similar to the structureand materials of the other graft embodiments discussed above. In oneparticular embodiment, the main body portion and legs of the graft aremade of expanded polytetrafluoroethylene (ePTFE) and the self-expandingmembers are made of nickel titanium, stainless steel or the like.

[0167] A first distal self-expanding member 422 is secured to the seconddistal self-expanding member 411 as shown in FIG. 19. This configurationis similar to that of endovascular graft 11 illustrated in FIGS. 1-6B,10-12 and 14-16 above. Graft 11 has first and second distalself-expanding members 32 and 33 that may be deployed in any desiredsequence. In a particular embodiment having first and second distalself-expanding members, it may be desirable to first deploy the seconddistal self-expanding member 33 prior to deploying the first distalself-expanding member 32. As discussed above, deploying the seconddistal self-expanding member 33 first may allow the operator toaccurately adjust the axial position of the graft in the body lumen orvessel to within one to several millimeters before deploying the firstdistal self-expanding member 32. Using this technique, deployment of thesecond distal self-expanding member 33 alone provides sufficientresistance to axial displacement of the graft 11 for the graft positionto be maintained in normal blood flow, but still allows deliberate axialdisplacement by the operator to achieve a desired axial position. Thismay be particularly important if tissue-penetrating members are includedon the distal-most or first distal self-expanding member 32. If suchtissue penetrating members are used on the first distal self-expandingmember 32, axial movement may be difficult or even impossible once thismember 32 is deployed without risking damage to the body lumen orvessel. As such, accurate axial placement of the graft 11 prior todeployment of the first distal self-expanding member 32 can be critical.

[0168] In addition, although not shown in the figures, this graftembodiment 401 may include two or more proximal self-expanding membersdisposed on one or both of the ipsilateral leg 404 and/or contralateralleg 405. These self-expanding members may have a configuration similarto that of the first and second distal self-expanding members 411 and422

[0169] FIGS. 23-32 illustrate an embodiment of a delivery system 400having features of the invention. FIG. 23 shows delivery system 400 inpartial section having an elongate shaft 423 with a proximal end 424, adistal end 425 and a distal section 426. A proximal adapter 427 isdisposed at the proximal end 424 of the elongate shaft 423 and housesthe controls that enable the operator to manipulate elements at thedistal section 426 of delivery system 400 to release and deploy thegraft 401, including inflating the graft channels 418 and cuffs 413, 414and 415. The elongate shaft 423 has an inner tubular member 430 and anouter tubular member 431 disposed about the inner tubular member 430.The outer tubular member 431 is generally configured to slide in anaxial direction over the inner tubular member 430. A proximal end 432 ofthe inner tubular member 430 is secured to or disposed on the proximaladapter 427. The inner and outer tubular members 430 and 431 may be madeof polymeric materials, e.g., polyimides, polyester elastomers(HYTREL®), or polyether block amides (PEBAX®), and other thermoplasticsand polymers. The outside diameter of the outer tubular member 431 mayrange from about 0.1 inch to about 0.4 inch; specifically from about0.15 inch to about 0.20 inch. The wall thickness of the outer tubularmember 431 may range from about 0.002 inch to about 0.015 inch,specifically from about 0.004 inch to about 0.008 inch. The proximaladapter 427 is generally fabricated from a polymeric material such aspolyethylene, acetal resins (DELRIN®), etc., but can also be made fromany other suitable material.

[0170] Bifurcated stent graft 401 is shown in FIGS. 23-28 disposedwithin the distal section 426 of the elongate shaft 423 in a constrainedconfiguration. The outer tubular member 431 is disposed about the graft401 in the constrained state but can be retracted proximally so as toexpose the constrained graft 401 by proximally retracting a proximal end433 of the outer tubular member 431. As illustrated more fully in FIG.37, a distal nosepiece 434 may be disposed on a distal end 435 of theouter tubular member 431 and forms a smooth tapered transition from aguidewire tube 436 to the outer tubular member 431. This transitionhelps to facilitate the tracking of the outer tubular member 431 over aguidewire 437. In order to form this smooth transition, the nosepiece434 may have a length to major diameter ratio ranging from about 3:1 toabout 10:1 (the “major diameter” being defined as the largest diameterof the nosepiece). The outer tubular member 431 is not typicallypermanently secured to the nosepiece 434 and may be retractable from thenosepiece 434 during the deployment sequence. A secondary release cable438 extends from an opening in the distal section of the elongate shaft.Nosepiece 434 may be grooved to receive secondary release cable 438 ifdesired.

[0171]FIG. 24 shows the inner tubular member 430 disposed within theouter tubular member 431 and the guidewire tube 436 disposed within theinner tubular member 430. The guidewire tube 436 may be made frompolymeric materials such as polyimide, polyethylene,polyetheretherketones (PEEK®), or other suitable polymers, and may havean outside diameter ranging from about 0.02 inch to about 0.08 inch,specifically about 0.035 inch to about 0.055 inch. The guidewire tube436 wall thickness may range from about 0.002 inch to about 0.025 inch,specifically from about 0.004 inch to about 0.010 inch.

[0172] A release member tube in the form of a release wire tube 441 isdisposed about a distal primary release member in the form of a distalprimary release wire 442. The release wire tube 441 is also disposedabout a proximal primary release member in the form of a proximalprimary release wire 443. Both the release member tube 441 and aninflation tube 444 are disposed within an inner lumen 445 of the innertubular member 430. The outside diameter of the release wire tube 441may range from about 0.01 inch to about 0.05 inch, specifically about0.015 inch to about 0.025 inch. The wall thickness of the release wiretube 441 may range from about 0.001 inch to about 0.006 inch,specifically from about 0.002 inch to about 0.004 inch.

[0173] The outside diameter of the inflation tube 444 may range fromabout 0.02 inch to about 0.10 inch; specifically from about 0.04 inch toabout 0.08 inch. The inflation tube 444 wall thickness may range fromabout 0.002 inch to about 0.025 inch; specifically from about 0.003 inchto about 0.010 inch.

[0174] In FIG. 25, a potted portion 446 is disposed between an innersurface 447 of a distal end 448 of the inner tubular member 430, therelease wire tube 441, the guidewire tube 436 and the inflation tube444. The potted portion 446 seals the inner lumen 445 of the innertubular member 430 from bodily fluids that are exposed to theconstrained graft 401 and potted portion 446 once the outer tubularmember 431 is proximally retracted. The potted portion 446 may be madefrom adhesives, thermoforming plastics, epoxy, metals, or any othersuitable potting material. Alternatively, a molded or machined plug maybe bonded or affixed to the distal end of the inner tubular member, withlumens to accommodate the passage of tubes 441, 436 and 444.

[0175] A more detailed view of the distal section 426 of the elongateshaft 423 is shown in partial section in FIGS. 26-30. A distal section451 of the guidewire tube 436 serves as a primary belt support member452 and is disposed within the main body portion 402 and ipsilateral leg404 of the graft 401. Alternatively, the primary belt support member 452may be disposed adjacent the graft main body portion 402 and ipsilateralleg 404. A secondary belt support member housing 453 is secured to theprimary belt support member 452. An additional length of guidewire tubeor other elongate member serving as a secondary belt support member 454is slidably disposed within an appropriately configured lumen 455 of thehousing 453. The secondary belt support member 454 is shown in FIG. 26disposed within the graft main body portion 402 and contralateral leg405; however, the secondary belt support member 454 may also be disposedadjacent the contralateral leg 405, regardless of whether the primarybelt support member 452 is disposed adjacent or within the main bodyportion 402 and ipsilateral leg 404.

[0176] The secondary belt support member housing lumen 455 and secondarysupport member 454 cross sections may be keyed, singly or incombination, to allow relative sliding motion without relative rotationmotion and therefore limit any twisting of the secondary support member454 and the contralateral leg 405. The secondary belt support member 454may be made from alloys such as nickel titanium, stainless steel, orpolymeric materials such as polyimide and can have an outside transversedimension ranging from about 0.01 inch to about 0.06 inch.

[0177] A proximal primary belt 456 is shown in FIG. 26 disposed aboutand radially constraining the proximal self-expanding member 407 of theipsilateral leg 404. This proximal self-expanding member 407 in turn isdisposed about a bushing 457 that is shown as cylindrical in form, butwhich may have other configurations as well. The bushing 457 is securedto the primary belt support member 452 adjacent the proximalself-expanding member 407 of the ipsilateral leg 404.

[0178] A first distal primary belt 458 is disposed about and radiallyconstraining the first distal self-expanding member 422, which itself isdisposed about a cylindrical bushing 461. A second distal primary belt462 is disposed about and radially constraining the second distalself-expanding member 411 and the second distal self-expanding member411 is disposed about a cylindrical bushing 463.

[0179] A secondary belt 464 is shown disposed about and radiallyconstraining the proximal self-expanding member 408 of the contralateralleg 405. This proximal self-expanding member 408 is disposed about abushing 465 that is cylindrical in shape.

[0180] As with the other embodiments of the present invention, the belts456, 458, 462 and 464 are typically made from nickel titanium, an alloythat is capable of exhibiting a unique combination of high strainwithout elastic deformation, high strength and biocompatability.However, any other suitable materials may be used including othermetallic alloys such as stainless steel, high strength fibers such ascarbon, KEVLAR®, polytetrafluoroethylene (PTFE), polyimide, or the like.The outer transverse dimension or diameter of the belts 456, 458, 462and 464 can be from about 0.002 inch to about 0.012 inch; specificallyabout 0.004 inch to about 0.007 inch.

[0181] A distal portion 466 of the proximal primary release wire 443 isdisposed within end loops 468 of the proximal primary belt 456 so as toreleasably secure the proximal self-expanding member 407 of theipsilateral leg 404 in a constrained state. The proximal primary belt456 may be disposed about the self-expanding member 407 in a hoop-likeconfiguration. The proximal self-expanding member 407 exerts outwardradial pressure on the releasably secured belt 456. The primary proximalrelease wire 443 is axially moveable within the end loops 468 of theproximal primary belt 456 to allow for release of the belt by proximalretraction of the primary proximal release wire 443 in the same manneras described above with respect to other embodiments of the presentinvention.

[0182] Likewise, a distal portion 471 of the distal primary release wire442 is disposed within end loops 472 of the second distal primary belt462 that radially constrains the second distal self-expanding member411. The second distal primary belt 462 is formed in a hoopconfiguration about the second distal self-expanding member 411 and thesecond distal self-expanding member 411 exerts outward radial force onthe second distal primary belt 462. The distal primary release wire 442is axially moveable within the end loops 472 of the second distalprimary belt 462 to allow for release of the radial constraint asdiscussed above with respect to the proximal primary release wire 443and as discussed above for other embodiments of the present invention.The distal portion 471 of the distal primary release wire 442 is alsodisposed within end loops 473 of the first distal primary belt 458 andradially constrains the first distal self-expanding member 422 in asimilar fashion.

[0183] Although the distal primary release wire 442 and proximal primaryrelease wire 443 are shown as two separate components, the release wires442 and 443 could be combined into a single release member, such as thebranched release wire 150 shown in FIG. 7I above. A branched releasewire is capable of releasing multiple belts in a desired sequence byproper configuration of the lengths of the various branches of the wire.The relative amount of the release wire extending beyond the looped endsof the belt as indicated by reference numeral 156 in FIG. 7I controlsthe timing of the release of the belts. Alternatively, a single releasewire may engage both distal and proximal primary belts 456, 458 and 462.As this single release wire 150 is moved proximally, the first distalprimary belt 458 is first released, followed by the release of thesecond distal primary belt 462 and then release of the proximal primarybelt 456.

[0184] A distal portion 474 of a secondary release member in the form ofa secondary release wire 475 is disposed within end loops 476 of asecondary belt 464 that radially constrains the proximal self-expandingmember 408 of the contralateral leg 405. The proximal self-expandingmember 408 of the contralateral leg 405 exerts outward radial force onthe secondary belt 464 when the self-expanding member 408 is in aconstrained configuration. The secondary release wire 475 is axiallymoveable within the end loops 476 of the secondary belt 464.

[0185] A proximal end 477 of the secondary release wire 475 is securedto an actuator hub 478. A release strand 481 is secured to the actuatorhub 478 and is attached to the secondary belt support member 454, and isshown by way of example in the embodiment of FIG. 26 as being loopedthrough a hole 482 in the proximal end 483 of the secondary belt supportmember 454. Both portions of the release strand 481 that are loopedthrough the proximal end 483 of the secondary belt support member 454pass into an inner lumen 484 of a release strand tube 485 as seen inFIG. 27. The release strand tube 485 passes through an aperture 486 inthe distal end 435 of the outer tubular member 431. Release strand 481may comprise any filamentary thread or wire, metallic, polymeric, orotherwise, suitable for manipulation as will be herein described. Italso may be braided or twisted if desired. The release strand 481 may bemade of a filamentary thread of ePTFE.

[0186] As discussed above with respect to other embodiments, the releasewires 442, 443 and 475 are generally made from a biocompatible highstrength alloy such as stainless steel, but can also be made from anyother suitable materials. Examples include other metallic alloys such asnickel titanium, non-metallic fibers such as carbon, polymericmaterials, composites thereof, and the like. As discussed above, thediameter and stiffness of the release wires 442, 443 and 475 can beimportant with respect to the diameter and stiffness of the belts 456,458, 462 and 464.

[0187] The configuration of the end loops 468, 472, 473 and 476 of thebelts 456, 458, 462 and 464 may vary to suit the particular embodimentof the delivery system 400 and device to be delivered. For example,FIGS. 7C-7H illustrate a variety of belt and end loop configurationsthat may be suitable for delivery systems for bifurcated devices.Referring to FIG. 7C, belts 112 and 114 are shown having a twistedconfiguration that has a tendency to reduce snagging or entanglement ofthe belts 112 and 114 after deployment and release of the belts from aconstrained configuration. In addition, FIG. 7C illustrates an angle αthat belts 112 and 114 make with respect to line 125. In one embodiment,belts 112 and 114 would be substantially parallel to each other when inan unconstrained state such that this angle is approximately ninetydegrees. It may also be desirable to use belts that have end loops thathave different cross sectional areas (or transverse dimensions). Forexample, FIG. 7E shows end loops 81′ and 81″ constrained by release wire24. We have found that, depending on the transverse dimension andmaterial of loop 81′ disposed within loop 81″, elastic deformation ofloop 81′ can hinder the release process when release wire 24 isproximally retracted. Therefore, it may be desirable to make loop 81′from a material that is substantially smaller in cross sectional area ortransverse dimension that that of loop 81″. In a particular example,loop 81′ is made from nickel titanium wire having a diameter of about0.003 to about 0.005 inch, and loop 81″ is made from the same materialhaving a diameter ranging from about 0.005 to about 0.007 inch.

[0188] Inflation port 421 extends proximally from the proximal end 416of the ipsilateral leg 404 of the graft 401. The inflation port 421 iscoupled to a distal end 487 of the inflation tube 444 by a retentionmechanism, such as a retention wire 488, the operation of which can bethe same or similar to like embodiments of retention wire 285 discussedabove.

[0189] Typically, the retention wire 488 extends from the inflation port421 proximally to the proximal adapter 427 of delivery system 400. Thedistal end 487 of the inflation tube 444 can be disengaged from theinflation port 421 by pulling on a proximal end 491 of retention wire488, as shown in FIGS. 23, 26 and 31. The retention wire 488 may be asmall diameter wire made from a material such as a polymer, stainlesssteel, nickel titanium, other alloy or metal, or composite; in aparticular embodiment of the invention, retention wire 488 may be aspring formed of a variety of suitable spring materials. Alternatively,the retention wire 488 may have a braided or stranded configuration.

[0190]FIG. 31 illustrates proximal adapter 427 which is suitable for usewith embodiments of the present invention. The proximal adapter 427houses the proximal termination of the primary release wires 442 and443, guidewire tube 436, retention wire 488 and release wire tube 441.The proximal adapter 427 has a first side arm 492 with an inner lumen493 that secures the proximal end 494 of the release wire tube 441 andsecond side arm 499 having an inner lumen in fluid communication withinflation material lumen 506 that houses proximal end 491 of retentionwire 488. The proximal adapter 427 has a distal primary release wirehandle 495 and a proximal primary release wire handle 496 that aredisposed in a nested configuration on the first side arm 492. A proximalend 497 of the proximal primary release wire 443 is secured to theproximal primary release-wire handle 496. A proximal end 498 of thedistal primary release wire 442 is secured to the distal primary releasewire handle 495. This configuration prevents the operator frominadvertently deploying or activating the proximal primary release wire443 prior to deployment or activation of the distal primary release wire442 which could result in an undesirable graft 401 deployment sequence.

[0191] A proximal end 501 of the guidewire tube 436 is secured within acentral arm 502 of the proximal adapter 427 that has a potted section503. A seal 504 may be disposed on a proximal end 505 of the central arm502 for sealing around the guidewire lumen and preventing a backflow offluid. The potted section 503 of the central arm 502 prevents anyinjected fluids from passing into the inflation material lumen 506within the proximal adapter 427 or the inner tubular member 430. Theother functions and features of the proximal adapter 427 may be the sameor similar to those of the proximal adapters 42 and 323 shown in FIG. 1and FIG. 17 and discussed above.

[0192]FIG. 32 illustrates a belt support member assembly 507 of thedelivery system 400. The distal end 508 of the secondary belt supportmember 454 is slidingly disposed within the secondary belt supportmember housing 453 that is secured to the primary belt support member452. The second distal primary belt 462 is secured to the primary beltsupport member 452 (which in this embodiment is the guidewire tube 436)and extends radially therefrom through an optional second distal primarystandoff tube 511. Similar optional first distal primary standoff tube512, proximal primary standoff tube 513 and optional secondary standofftube 514 are disposed on the first distal primary belt 458, proximalprimary belt 456 and secondary belt 464, respectively.

[0193] In general, the various features and components (including, e.g.,details of various embodiments of the release wires, the self-expandingmembers, belts, inflation port and tube, guidewire tube, standoff tubes,proximal adapter and its associated components, the materials anddimensions for each of the various components, etc.) as discussed hereinwith respect to those embodiments of FIGS. 1-18 may be used in thebifurcated embodiments of the present invention as discussed herein andas illustrated in FIGS. 19-32.

[0194] In use, the delivery system 400 for delivery of a bifurcatedintracorporeal device, specifically, a bifurcated graft 401, can beoperated in a similar fashion to the delivery systems discussed above.FIG. 33 illustrates generally the anatomy of a patient's heart 515,aorta 516 and iliac arteries 517. The aorta extends from the heart 515and descends into the abdomen of the patient's body. An aneurysm 518 isdisposed in the aorta 516 just below the renal arteries 519. The aorta516 branches into the right and left iliac arteries 517 below theaneurysm, which then become the femoral arteries 520.

[0195] One delivery procedure of the present invention begins withdelivery of a first guidewire 530 into an access hole 531 in a femoralartery, the right femoral artery 532 for the procedure depicted in FIG.34, and advanced distally through the iliac artery 517 and into thepatient's aorta 516. Access into the femoral artery 532 is generallyaccomplished with a standard sheath and trocar kit, although sheathlessaccess may also be employed. It should be noted that although theprocedure described herein and illustrated in FIGS. 34-52 is initiatedin the right femoral artery 532, the same procedure could be carried outbeginning in the left femoral artery 533 with the orientation reversed.A vasodilator may optionally be administered to the patient at thispoint as previously discussed. If desired, a vasodilator may also beadministered later in the procedure, but preferably prior to orsimultaneous with the step of introducing inflation material into thegraft 401.

[0196] With the first guidewire 530 positioned across the aneurysm 518,a second guidewire 534 is then introduced into the ipsilateral or rightfemoral artery 532 and guided into the iliacs 517 and then back downinto the contralateral or left femoral artery 533 as shown in FIG. 35. Adistal end 535 of the second guidewire 534 may then be captured with asnare 536 or similar device inserted through an access hole 537 in theleft femoral artery 533. The distal end 535 of the second guidewire 534may then be pulled out of the left femoral artery 533 through the sameleft femoral artery access hole 537, providing a continuous length ofwire passing through each iliac artery 517 via the left and rightfemoral artery access holes 537 and 531 as shown in FIG. 35.

[0197] Once the second guidewire 534 exits the access hole 537 in theleft femoral artery 533, a tubular catheter 538 may be advanced over thesecond guidewire 534 through the left femoral artery access hole 537 soas to extend out of the body from the access hole 531 in the rightfemoral artery 532 as shown in FIG. 36. This provides a continuousconduit between the right and left iliac arteries 517. With a distal end541 of the tubular catheter 538 extending from the access hole 531 inthe right femoral artery 532, a distal end 542 of the secondary releasecable 438 may then be affixed to a proximal end 543 of the secondguidewire 534 as shown in FIG. 37. For purposes of simplicity, thesecondary release cable 438 is shown in, e.g., FIGS. 37-40 in schematicform as a single strand. However, it is understood that the term“secondary release cable” encompasses a single or multiple-componentfeature of the present invention that may be used to assist in thedeployment of the graft. For instance, in the embodiment depictedherein, the secondary release cable 438 represents the combination ofthe release strand 481 and release strand tube 441 discussed above inconjunction with, e.g., FIG. 26. Other variations of this combinationare within the scope of the present invention.

[0198] The second guidewire 534 is then pulled out of the tubularcatheter 538 from the left femoral artery access hole 537, in thedirection indicated by the arrow 544 in FIG. 37, so that the secondaryrelease cable 438 then extends through the tubular catheter 538 from theright iliac artery to the left iliac artery. The tubular catheter 538may then be withdrawn, leaving the secondary release cable 438 extendingthrough the left and right iliac arteries 517 from the access hole 531in the right femoral artery 532 to the access hole 537 in the leftfemoral artery 533 as shown in FIG. 38. The first guidewire 530 remainsin position across the aneurysm 518.

[0199] The delivery system 400 is then advanced into the patient's rightfemoral artery 532 through the access hole 531 over the first guidewire530 as shown in FIG. 39. It may be desirable to apply tension to thesecondary release cable 438 as the delivery system 400 is advanced tothe vicinity of the aneurysm 518 so as to remove slack in the cable 438and prevent tangling of the cable 438 or the like. Tension on thesecondary release cable 438 may also help to prevent twisting of thedelivery system 400 during insertion.

[0200] FIGS. 37A-B show an optional marker band that may disposedadjacent nosepiece 434 or generally in the vicinity of the distal end ofthe delivery system 425. Such a marker band 551 may also be integralwith the delivery system 400; for example, it may be incorporated aspart of the distal nosepiece 434. A useful marker 551 can be one thatdoes not add to the profile of the delivery system 400 as shown in FIG.37A (i.e., one that does not give the delivery system 400 a higherdiameter). The embodiments of FIGS. 37A-B are useful in the presentembodiment, although they may be used in the embodiments discussedabove. Such a marker may be used to aid the operator in introducing thedelivery system 400 without twisting.

[0201] For example, the marker embodiment 551 of FIG. 37A comprises amarker body 552 in the form of a simple discontinuous ring made of anappropriate radiopaque material (e.g., platinum, gold, etc.) visibleunder fluoroscopy, etc. The cross section of the ring may be asymmetricso that under fluoroscopy the cross section may be seen in the vicinityof the discontinuity 553. The operator will be able to tell if thedelivery system 400 is twisted by how the ring 552 is presented underfluoroscopy. Alternatively, ring 552 may be continuous but have a notchor similar cutout to serve the same purpose.

[0202] The embodiment 554 of FIG. 37B is an example of such a marker.Here, both a notch 555 and two circular holes 556 have been cut out ofthe marker body 557 for easier determination of its orientation whendisposed on the notch or other part of the delivery system 400. Forinstance, in an orientation where the two circular holes 556 are alignedwith respect to the fluoroscope field of view, the user will see asingle circular hole to the left of a triangular or vee-shape cutout 555on the side of the marker 554. As the angular orientation of the device400 (and thus the marker 554) about the longitudinal axis changes, theappearance of the two circular holes 556 and side notch 555 will change.If the device is twisted clockwise ninety degrees from this orientationalong its central longitudinal axis 554A, for instance, the circles 556will largely disappear from view and the side notch 555 will generallyappear in the front of the field of view as a symmetric diamond.Comparing these views will allow the user to know that the entiredelivery system 400 has twisted about ninety degrees. Keeping the sameorientation, then, will be made easier with such a marker 554.

[0203] For each of the embodiments of FIGS. 37A-B, variations in theshape, number, orientation, pattern and location of the notch 553 and555, holes 556 or other discontinuity, as well as various marker bodydimensions cross sectional shape, etc., may be realized, as long as themarker 551 and 554 is configured so that the angular orientation of thedelivery system 400 may readily be determined by the user underfluoroscopy or similar imaging technique.

[0204] The delivery system 400 is positioned in a location suitable forinitiating the deployment process, such as one in which the distal end425 of the delivery system 400 is disposed beyond, or distal to theposition in which the graft 401 will be placed, as shown in FIG. 40.This position allows the proximal end 483 of the secondary belt supportmember 454 to be laterally displaced without mechanical interferencefrom the patient's vasculature. Such clearance for lateral displacementis shown in FIG. 44.

[0205] Once the distal section 426 of the elongate shaft 423 and theendovascular graft 401 are positioned, the deployment process isinitiated. First, the outer tubular member 431 is proximally retractedby pulling on the proximal end 433 of the outer tubular member 431relative to the inner tubular member 430. The inner tubular member 430should be maintained in a stable axial position, as the position of theinner tubular member 430 determines the position of the constrainedbifurcated graft 401 prior to deployment. Upon retraction of the outertubular member 431, the constrained bifurcated graft 401 is exposed andadditional slack is created in the secondary release cable 438 as shownin more detail in FIG. 41.

[0206] Alternatively, a variety of different components may besubstituted for the outer tubular member 431 in some of the embodimentsof the invention. For instance, a shroud, corset, mummy-wrap, or othercover may be released or actuated to expose the constrained graft 401after the delivering system 400 is introduced into the vasculature.

[0207] The slack in the secondary release cable 438 is taken up byapplying tension to both lengths 561 and 562 of the release strand 481as shown by the arrows 563 in FIG. 41. In alternative embodiments,release strand is not continuous such that lengths 561 and 562 each hasa free end, each of which may be manipulated by the operator. As tensioncontinues to be applied to both lengths 561 and 562 of the releasestrand 481, the secondary belt support member 454 begins to slide withinthe secondary belt support member housing 453 in a proximal direction asshown by the arrow 564 in FIG. 42. The secondary belt support member 454continues to slide proximally until all the slack is removed from anaxially compressed or folded portion 565 of the contralateral leg 405 ofthe graft 401 shown in FIG. 41 and the primary and secondary beltsupport members 452 and 454 are oriented relative to the secondary beltsupport member housing 453 as generally shown in FIG. 43. Rotationalmovement of the secondary belt support member 454 relative to thesecondary belt support member housing 453 is prevented by thenon-circular or asymmetric cross section of the member 454 as shown inFIGS. 28-28B. This prevents the contralateral leg 405 from twisting orbecoming entangled with other components of the graft 401 or deliverysystem 400 during deployment.

[0208] Axial compression of all or a portion of the contralateral leg405 while the graft 401 is in a constrained state within the deliverysystem 400 prior to deployment allows the axial position of the twoproximal self-expanding members 407 and 408 to be axially offset fromeach other. Alternatively, graft legs 404 and 405 having differentlengths may be used to prevent overlap of the self-expanding members 407and 408 within the delivery system 400. The cross sectional profile orarea of the overlap self-expanding members 407 and 408 is generallygreater than that of the adjacent polymer material portion of the legs404 and 405 of the graft 401, so eliminating the overlap can bedesirable. The self20 expanding members 407 and 408 are typically madeof a metal or metallic alloy and maintain a cylindrical configuration,even when in a constrained state. The polymer material of the legs 404and 405 or main body portion 402 of the graft 401, by contrast, isrelatively soft and malleable and can conform to the shape of whateverlumen in which it may be constrained. Placing both proximalself-expanding members 407 and 408 adjacent each other in a compressedstate at a single axial position within the delivery system 400 wouldrequire a configuration in which two objects having an approximatelycircular cross section are being placed within another circular lumen.Such a configuration generates a significant amount of wasted or unusedcross sectional area within that axial position of the delivery system400 and would likely result in less flexibility and greater crosssection than a delivery system 400 in which the proximal self-expandingmembers 407 and 408 are axially offset.

[0209] A gap 566 indicated by the arrows 567 in FIG. 44 allows theproximal end 483 of the secondary belt support member 454 and secondaryrelease wire actuator hub 478 to move in a lateral direction withoutmechanical interference from the carina 568 of the iliac arterybifurcation 569. Gap 566 may vary depending on the patient's particularanatomy and the specific circumstances of the procedure.

[0210] The lateral movement of the contralateral leg 405 and secondarybelt support member 454 is accomplished by application of tension onboth lengths 561 and 562 of the release strand 481 as shown by thearrows 571 in FIG. 44. This movement away from the primary belt supportmember 452 allows the secondary belt support member 454 to transitionfrom alignment with the right iliac artery 572 to alignment with theleft iliac artery 573 as shown in FIG. 44.

[0211] Once the ipsilateral leg 404 of the graft 401 and contralateralleg 405 of the graft 401 are aligned with the right and left iliacarteries 572 and 573, respectively, the delivery system 400 may then beretracted proximally, as shown by the arrow 574 in FIG. 45, so as toreposition the distal section 426 of the elongate shaft 423 and thebifurcated graft 401 into the desired position for deployment as shownin FIG. 45.

[0212] As discussed above with respect to placement of a tubular graft11 embodiment of the present invention, when deploying the graft 401 inthe abdominal aorta 516 it is generally desirable to ensure that thedistal end 403 of the graft main body portion 402 is installed proximalto, or below, the renal arteries 519 in order to prevent theirsignificant occlusion. However, the distal self-expanding members 411and 422 of the graft 401 may, depending upon the anatomy of the patientand the location of the aneurysm 518, partially or completely span theostia 575 of one or both renal arteries 519. It can be desirable,however, to ensure that ostia 575 of the renal arteries 519 are notblocked by the distal end 403 of the graft main body portion 402. Asdiscussed previously, a variety of imaging markers 551 and 554 may beused on either or both the delivery system 400 and the graft 401 itselfto help guide the operator during the graft positioning process.

[0213] After proper positioning, the first and second distalself-expanding members 411 and 422 may then be deployed. The operatorfirst unscrews or otherwise detaches a threaded portion 576 of thedistal primary release wire handle 495 from an outer threaded portion577 of a first side arm end cap 578 shown in FIG. 31. Next, the distalprimary release wire handle 495 is proximally retracted, which in turnretracts the distal primary release wire 442 in a proximal direction, asshown by the arrow 581 in FIG. 46. As the distal end 582 of the distalprimary release wire 442 passes through the end loops 472 and 473 of thefirst distal primary belt 458 and second distal primary belt 462, theend loops 472 and 473 are released, freeing the first distalself-expanding member 422 and second distal self-expanding member 411 toself-expand in an outward radial direction so to contact an innersurface 583 of the patient's aorta 516. The first and second distalprimary belts 458 and 462 remain secured to the primary belt supportmember 452 and will eventually be retracted from the patient with thedelivery system 400 after deployment is complete.

[0214] As the first and second distal self-expanding members 411 and 422expand and contact the aorta 516, a distal end 403 of the graft mainbody portion 402 opens with the self-expanding members 411 and 422 andpromotes opening of the graft polymer material portion from the flow ofblood into the distal end 403 of the graft main body portion 402 with a“windsock” effect. As a result, once the first and second distalself-expanding members 411 and 422 are expanded to contact the aortainner surface 583, the graft main body portion 402 and legs 404 and 405balloon out or expand while the proximal ends 416 and 417 of the legs404 and 405 of the graft 401 remain constricted due to the constrainedconfiguration of the proximal self-expanding members 407 and 408 of theipsilateral and contralateral legs 404 and 405, as shown in FIG. 46. Atthis point, there typically will be partial or restricted blood flowthrough and around the graft 401.

[0215] Bifurcated graft 401 may then be optionally be inflated with aninflation material via inflation tube 444 and inflation port 421 untilthe inflatable channels 418 and inflatable cuffs 413, 414 and 415 havebeen filled to a sufficient level to meet sealing and other structuralrequirements necessary for the bifurcated graft main body portion 402and the ipsilateral and contralateral legs 404 and 405 to meet clinicalperformance criteria. As described in later conjunction with analternative embodiment of the present invention, inflating the graft 401prior to deploying the proximal and distal self-expanding members 407and 408, respectively, is useful in anatomies where the vasculature istortuous or angled.

[0216] Next, the proximal self-expanding member 407 of the ipsilateralleg 404 is deployed. Deployment of the first and second distalself-expanding member 411 and 422 has exposed the proximal primaryrelease wire handle 496, making it accessible to the operator. Athreaded portion 584 of the proximal primary release wire handle 496 isunscrewed or otherwise detached from an inner threaded portion 585 ofthe first side arm end cap 578. The proximal primary release wire handle496 may then be retracted proximally so as to deploy the proximalprimary belt 456 and proximal self-expanding member 407 of theipsilateral leg 404 as shown in FIG. 47.

[0217]FIG. 48 depicts an enlarged view of the proximal end 483 of thesecondary belt support member 454. The proximal self-expanding member408 of the contralateral leg 405 is secured to the proximal end 417 ofthe contralateral leg 405. The proximal self-expanding member 408 isconstrained in a radial direction by the secondary belt 464, which hasend loops 476 releasably constrained by the distal end 587 of thesecondary release wire 475. The proximal end 477 of the secondaryrelease wire 475 terminates with and is secured to the actuator hub 478.The release strand is secured to the actuator hub 478 and loops throughan aperture or hole 482 in the proximal end 483 of the secondary beltsupport member 454. As discussed above, a portion of the release strand481 is disposed within the release strand tube 485 to form the secondaryrelease cable 438.

[0218] When both a first length 561 and second length 562 of the releasestrand 481 are pulled together in a proximal direction from a proximalend 588 of the secondary release cable 438, the entire pulling force isexerted on the proximal end 483 of the secondary belt support member 454because the looped distal end 542 of the release strand 481 pulls on theproximal end 483 of the secondary belt support member 454 withoutdisplacing the actuator hub 478.

[0219] When deployment of the proximal self-expanding member 408 of thecontralateral leg 405 is desired, the operator applies tension in aproximal direction only to the first length 561 of the release strand481, which extends proximally from the actuator hub 478. The directionof such tension is indicated in FIG. 48 by the arrows 591. Upon theapplication of this proximal tension, the actuator hub 478 is movedproximally, as is the secondary release wire 475 that is secured to theactuator hub 478. The proximal self-expanding member 408 of thecontralateral leg 405 deploys when the distal end 587 of the secondaryrelease wire 475 passes through the end loops 468 of the secondary belt464 so as to release the radial constraint on the proximalself-expanding member 408 imposed by the secondary belt 464. Uponrelease of the radial constraint, the proximal self-expanding member 408expands so as to contact an inside surface 592 of the left iliac artery573 as shown in FIG. 49. Once the proximal self-expanding member 408 ofthe contralateral leg 405 is expanded, the operator may then applytension to both lengths 561 and 562 of the release strand 481 towithdraw the secondary belt support member 454 from the housing 453 (asshown in FIG. 50) and remove it from the patient's vasculature throughthe left femoral artery access hole 537.

[0220]FIG. 51 depicts an alternative embodiment of a belt support memberassembly 600 in which the secondary belt support member 601 is detachedfrom the primary belt support member 602 by withdrawal of a latch wire603. Generally, all other features of the delivery system 604 of theembodiment of FIG. 51 can be the same as the delivery systems discussedabove. It should be noted, however, that the embodiment shown in FIG. 51does not allow the secondary belt support member 601 to slide in anaxial direction relative to the primary belt support member 602. Assuch, it may be desirable to use this embodiment to deliver and deploy agraft having legs that are not substantially equal in length. Otherwise,if proximal self-expanding members are to be axially offset, thesecondary belt support member 601 would have to be detached from theprimary belt support member 602 prior to deploying and releasing thesecondary belt (not shown).

[0221] In another configuration (not shown), a similar retention orlatch wire 603 passes through aligned aperatures in the secondary beltsupport member 454 and a housing, such as secondary belt support memberhousing 453 of FIG. 43. Linear and rotational motion of secondary beltsupport member 454 relative to primary belt support member 452 isprevented until wire 603 is withdrawn, freeing member 454 to be removedfrom housing 453. Typically the aperatures are disposed at an angle(such as about 45 degrees) relative to the surface of the membersthrough which they reside so to minimize the angles through whichretention wire 603 turn as is passes through the apertures. Retentionwire may double as the primary proximal release wire for one or both ofproximal self-expanding members 411 and 422.

[0222]FIG. 52 shows an alternative belt support member assembly 606wherein the secondary belt support member 607 is laterally displaced andlocked into a position parallel with the primary belt support member 608prior to removal of the delivery system 609 from the patient'svasculature. All other features of the delivery system 609 of theembodiment of FIG. 52 can be the same as the delivery systems discussedabove. In use, after all self-expanding members have been deployed, thedelivery system 609 is advanced distally into the patient's vasculature,as shown by the arrow 610 in FIG. 52, in order to achieve a gap betweena proximal end 611 of the secondary belt support member 607 and thepatient's vasculature as shown by the arrows 612 in FIG. 52. Aconstraining ring 613 is then retracted proximally, as indicated by thearrow 614, so as to force the secondary belt support member 607 to belaterally displaced as shown by the arrow 615, also in FIG. 52. Once thesecondary belt support member 607 has been fully retracted in a lateraldirection so as to be substantially parallel to the primary belt supportmember 608, the delivery system 609 can then be retracted from thepatient's vasculature.

[0223] If not previously filled, the bifurcated graft 401 may thereafterbe inflated with an inflation material described with respect to thetubular graft embodiment 11.

[0224] For all the embodiments described, both tubular and bifurcated,inflation is generally accomplished by inserting or injecting, via oneor more device such as a syringe or other suitable mechanism, theinflation material under a pressure- or volume-control environment.

[0225] For instance, in one embodiment of a pressure-control technique,a volume of inflation material is first injected into the deliverysystem 400 (which at this point may include the graft, but may alsoinclude the inflation tube 444). The particular desired volume ofinflation material will depend on several factors, including, e.g., thecomposition and nature of the inflation and polymer graft material, thesize of the graft 401 to be deployed, the vessel or lumen diameter intowhich the graft 401 is deployed, the configuration of the graft 401(tubular, bifurcated, etc.), the features of the graft main body 402 and(if present) legs 404 and 405, and the conditions during the procedure(such as temperature).

[0226] Thereafter, the operator may affix a pressure control device,such as an inflation syringe, to the injection port 621 of the proximaladapter 427 of the inflation tube and apply a pressure to the deliverysystem 400 and a graft 401 for a period of time. This serves to ensurethat the fill material previously introduced enters the graft 401 andfills it to the desired pressure level.

[0227] We have found that a useful pressure-control approach involves aseries of such constant pressure applications, each for a period oftime. For instance, the graft 401 may first be pressurized at a levelfrom about 5 psi to about 12 psi or higher, preferably about 9 psi, forbetween about 5 seconds and 5 minutes, preferably about 3 minutes ormore. Optional monitoring of the fluid and the device during the fillprocedure may be used to help ensure a proper fill. Such monitoring maybe accomplished under fluoroscopy or other technique, for instance, ifthe fill material is radiopaque.

[0228] Thereafter, the fill protocol may be completed, or the pressuremay be increased to between about 10 psi and about 15 psi or higher,preferably about 12 psi, for an additional period of time ranging frombetween about 5 seconds and 5 minutes or more, preferably about 1minute. If the graft 401 so requires, the pressure may be increased oneor more additional times in the same fashion to effect the proper fill.For instance, subsequent pressure may be applied between about 12 and 20psi or more, preferably about 16 psi to 18 psi, for the time required tosatisfy the operator that the graft 401 is sufficiently filled.

[0229] The details of particular pressure-time profiles, as well aswhether a single pressure-time application or a series of suchapplications is used to fill embodiments of the graft 401 will depend onthe factors described above with respect to the volume of fill materialused; the properties and composition of the fill material tend to be ofsignificance in optimizing the fill protocol. For example, a steppedseries of pressure-time profiles as described above is useful when thefill material comprises a hardenable or curable material whose physicalproperties may be time-dependent and which change after being introducedinto the graft 401 and its delivery system 400.

[0230] Alternatively, a volume-control method may be utilized to fillembodiments of the grafts 11 and 401, including both tubular andbifurcated. Here, a volume of fill material is again introduced into thedelivery system 400 as described above. In this method, however, thevolume of fill material used is precisely enough material to fill thegraft 401, the inflation tube 444, and any other component in thedelivery system 400 through which the fill fluid may travel on its wayto the graft 401. The operator introduces the predetermined quantity offill material, preferably with a syringe or similar mechanism, into theinflation tube 444 and graft 401. A precise amount of fill material maybe measured into a syringe, for example, so that when the syringe isemptied into the delivery system 400 and graft 401, the exact desiredamount of fill material has reached the graft 401. After a period oftime (which period will depend on the factors previously discussed), thesyringe or equivalent may be removed from the inflation tube 444 orinjection port 621 of proximal adapter 427 and the procedure completed.

[0231] A pressurized cartridge of gas or other fluid may be used in lieuof a syringe to introduce the fill material into the delivery system andgraft under this volume-control regime so to provide a consistent andreliable force for moving the fill material into the graft 401. Thisminimizes the chance that variations in the force and rate of fillmaterial introduction via a syringe-based technique affect the fillprotocol and possibly the clinical efficacy of the graft 401 itself.

[0232] For each of the pressure- and volume-control configurations, anoptional pressure relief system may be included so to bleed any air orother fluid existing in the delivery system 400 prior to theintroduction of the fill material (such as the inflation tube 444 orgraft 401) so to avoid introducing such fluid into the patient. Such anoptional system may, for example, comprise a pressure relief valve atthe graft 401/inflation tube 444 interface and a pressure relief tubedisposed through the delivery system 400 (e.g., adjacent the inflationtube 444) terminating at the proximal adapter 427 and vented to theatmosphere.

[0233] When graft 401 is deployed in certain anatomies, such as thosewhere the iliac arteries are tortuous or otherwise angled, the lumen ofone or more of graft inflatable cuffs 413, 414 and 415 and channels 418of may become pinched or restricted in those portions of the graft 401experiencing a moderate or high-angle bend due to the tortuosity of thevessel into which that portion of graft 401 is deployed. This reductionor even elimination of cuff/channel patency can hinder and sometimesprevent adequate cuff and channel inflation.

[0234] In addition, graft 401 main body 402 and/or legs 404, 405 may,upon initial retraction of outer tubular member 431 and deployment intothe vasculature, resist the “windsock” effect that tends to open up thegraft to its nominal diameter. Then in turn may lead to inadequate cuff413, 414, and 415 and channel 418 patency prior to their injection withinflation material. The windsock effect has a higher likelihood of beinghindered when graft 401 is deployed in relatively tortuous or angledanatomies; however, it may also be made more difficult when graft 401(and even tubular graft embodiments such as graft 11) is deployed inrelatively non-tortuous anatomies.

[0235] To address this issue, we have found it useful to incorporate anoptional ripcord or monofilament into the inflatable channel 418.Pre-loading such a ripcord 510 into all or a portion of the channel 418that runs along graft ipsilateral leg 404 and main body portion 402promotes effective inflation of the graft cuffs and channels as will bedescribed below in detail.

[0236] Ripcord 510 extends in one embodiment from distal cuff 413through channel 418, proximal cuff 414 and inflation port 421, andcontinues through inflation tube 444 and through second side arm 499 ofproximal adapter 427 as shown in FIG. 31A. A flexible fill catheter 523may be affixed to end of second side arm 499 at injection port 509.

[0237] Ripcord 510 extends through injection port 509 and catheter 523where it is affixed to a removable Luer-type fitting or cap 521 atcatheter 523 terminus 525 (which can serve as an injection port).Alternatively, in lieu of catheter 523, fitting 521 may be removablyconnected directly to injection port 509. Fill catheter may compromisean optional pressure relief valve (not shown).

[0238] In use, after graft 401 has been deployed into the vasculaturebut prior to injecting the inflation material through second side arm499, the operator removes fitting 521 from catheter 523 and pullsripcord 510 proximally out of the ipsilateral graft channel 418, secondside arm 499 and out through the end of catheter 523. This leaves behindan unobstructed lumen in channel 418 through which inflation materialmay pass as it is injected into the device, despite any folds, wrinkles,or angles that may exist in graft 401 due to vessel tortuosity orangulation, lack of windsocking, or other phenomena. Inflation materialmay then be injected into channel 418 and cuffs 413, 414 and 415 throughsecond side arm 499 as described elsewhere herein. Inflation materialpasses through the lumen in channel 418 left behind after ripcord 510 isremoved and reaches distal cuff 413. As cuff 413 fills, a hemostaticseal is created at distal end of graft 401 which promotes the desiredwindsocking of the graft. This in turn promotes the effective filling ofthe rest of the cuffs 414, 415 and channels 418 and any other lumens inwhich the inflation material may be directed.

[0239] Suitable materials for ripcord 510 include polymericmonofilaments, such as PTFE, Polypropylene, nVion, etc. Metallicfilaments such as stainless steel, nickel titanium, etc. may be used aswell. The diameter of ripcord 510 should be small compared to thediameter of channel 418 lumen to minimize impact on delivery systemprofile, yet large enough to permit reasonable flow of inflationmaterial into channel 418 lumen following its removal. We have foundthat a ripcord 510 diameter of between about 0.005 inch and 0.025 inchto be appropriate; in particular, a ripcord diameter of about 0.015 inchis suitable.

[0240] Alternatively, or in conjunction with ripcord 510, one or morepermanent monofilament lumen patency members or beads may beincorporated into one or more of the cuffs and channels to facilitatethe inflation process. We have found it useful to incorporate a singlebead into graft contralateral leg 405 channel 418 along with ripcord 510in the graft ipsilateral leg 404 channel 418.

[0241]FIG. 31B is a simplified cross sectional schematic view ofcontralateral leg 405 inflatable channel 418 having a bead 520 disposedin a lumen 522 of channel 418, taken along line 31B-31B in FIG. 19.Typically bead 520 extends from proximal cuff 414 to distal cuff 413,although it may be disposed in only a portion of channel 418 or in othercuffs or channels of graft 401.

[0242] Channel 418 is shown in FIG. 31B as bent or angled out of theplane of the page to simulate contralateral limb 405 placement in ahighly angled iliac artery. Under such bending forces, the walls 524 ofchannel 418 tend to close on lumen patency member 520, reducing the sizeof lumen 522 to be confined to the areas indicated in FIG. 31B. As canbe seen, bead 520 prevents the lumen 522 from collapsing to the pointwhere lumen 522 loses patency sufficient for satisfactory passage ofinflation material.

[0243] Bead 520 may have the same dimensions and comprise materials thesame as or similar to ripcord 510. In particular, we have found a PTFEbead having a diameter of about 0.020 inch to be useful in the channel418 embodiments of the present invention.

[0244] We have found that incorporating a ripcord 510 and/or one or morelumen patency members 520 in the system of the present inventionenhances the likelihood that graft cuffs and channels will reliably andsufficiently fill with inflation material. In one extreme experimentdesigned to test the feasibility of this concept, a bifurcated graftcontralateral leg 405 having a bead 520 disposed in the contralaterallimb channel 418 was tied into a knot at the leg proximal end 417.Inflation material was injected through ipsilateral leg inflation port421 under a pressure-control protocol. All cuffs and channels of graft401, including contralateral leg channel 418 and proximal cuff 415,filled completely without having to increase the fill pressure beyondnormal levels.

[0245] Although the benefits of ripcord 510 and one or more beads 520(together or in combination) may be most readily gained when graft 401is deployed in tortuous or highly angled anatomies, these components arealso useful in grafts deployed in relatively straight and non-tortuousanatomies. They may also be used in tubular stent-grafts of the presentinvention.

[0246] Turning now to FIG. 53, an embodiment of a bifurcated graftdelivery system 625 and method is illustrated. This embodiment istailored to provide for a controlled withdrawal of a secondary releasecable from a lumen of an inner tubular member 628 so to help eliminatethe possibility that the release cable 626 becomes entangled orotherwise twisted during deployment.

[0247] Shown in FIG. 53 is a well 633 is disposed in the inner tubularmember 628. Well 633 contains a release strand 629 that is looped at itsproximal end 634 outside the well 633 through an aperture 635 in thesecondary belt support member 636 and that is affixed or attached at itsdistal end 637 to a second guidewire 638. The second guidewire 638 isshown in the embodiment of FIG. 53 as disposed in its own optional lumen639 within the inner tubular member 628.

[0248] Within the well 633, the release strand 629 is arranged to form a“u-turn” in which it changes direction to double back on itself atjuncture 641 as shown in FIG. 53. At juncture 641, a friction line 642is looped around all or a portion of the release strand 629. Thisfriction line 642 is fixed to the bottom of the well 633 on one end 642Aand is free on another end 642B. The friction line 642 is preferably apolymeric monofilament such as polyimide, etc., but may be metallic andmay be braided as necessary to achieve the desired frictioncharacteristic needed to interact with release strand 629. Friction line642 has a length sufficient to interact with the release strand 629during the deployment process until the release strand 629 has beencompletely removed from the well 633 as will now be described in detail.

[0249] In use, the configuration of FIG. 53 works as follows. Once theleft and right femoral access holes 531 and 537, discussed above, havebeen created, the delivery system 625 is introduced into and through thepatient's vasculature. A snare catheter 643 is introduced into the leftfemoral artery access hole, such as the left femoral artery access hole537 discussed above. The operator then captures the tip 644 of thesecond guidewire 638 with the snare 643. In the embodiment of FIG. 53,the second guidewire 638 is shown as pre-attached to the release strand629 at the distal end 637.

[0250] A ball capture tip 638A or similar member may optionally bedisposed on the tip 644 of second guidewire 638 to facilitate itscapture by snare catheter 643 and prevent possible injury to the vesselintima. In addition, tip 638A may be made radiopaque so that it may bereadily located by the operator during the procedure. When in the formof a ball, tip 638A may have a diameter ranging from between about 0.020inch to about 0.120 inch, specifically, between about 0.040 inch toabout 0.060 inch. Although not shown in the figures, second guidewire638 may also have one or more additional sections branching therefrom,each having a tip or member similar to tip 644, including tip 638A, soto provide the operator with one or more alternative sites for capturewith snare 643 in case tip 638A is inaccessible.

[0251] An angled extension 639A may optionally be provided on one orboth of the top of optional lumen 639 and/or the top of well 633. Angledextension 639A may be made of any suitable polymeric or metallicmaterial such as stainless steel. As seen in FIGS. 53-54, extension 639Adisposed on the top of lumen 639 is generally biased towards the arteryin which snare 643 is disposed at an angle of between about 20 degreesand about 120 degrees, specifically, between about 40 degrees and about95 degrees, so to guide the release strand 629 and 653 in the properdirection and thus facilitate ease of capture by snare 643.

[0252] As the second guidewire 638 is pulled out of the inner tubularmember 628 from the left femoral artery access hole 537 in the directionshown by the arrow 544 in FIG. 37, the release strand 629 feeds out ofthe well 633 in an orderly and linear fashion in a direction from therelease strand distal end 637 to its proximal end 634. This is madepossible by the forces created at the “u-turn” or juncture 641 by thephysical interface with the friction line 642. The friction force (whichcan be tailored by the proper combination of release strand 629 andfriction line 642 diameters and their materials and by properlydimensioning of the well 633, for example) provides enough resistance tocounter the force applied by the operator so that the “u-turn” orjuncture 641 moves in an orderly fashion in a direction from the wellbottom 633 to the distal end 646 of the inner tubular member 628 untilit exits out of the outer tubular member 628. At this point, anyremaining friction line 642 at the juncture 641 is superfluous as it hasserved its purpose of facilitating an orderly withdrawal of the releasestrand 629. The operator continues to pull on the second guidewire 638as previously described so that the release strand 629 extends throughthe left femoral artery access port 537. We have found the embodiment ofFIG. 53 to be useful in achieving an orderly and tangle-free deployment.

[0253] Alternatively, any number of other arrangements in which therelease strand 629 may be fed out of the outer tubular member 628 in anorderly manner is within the scope of the present invention. Forinstance, the well 651 shown in FIGS. 54-56 is, for instance, anextruded polymeric part having a unique cross-sectional configurationthat eliminates the need for the friction line 642 in the embodimentshown in FIG. 53. Here, a narrowing constraint or gap 652 runs thelength of the well interior 651, forming a physical barrier betweenfirst and second opposing portions 654 and 655 of the release strand653, shown in FIGS. 54-56. The constraint or gap 652 is sized to allowthe passage therethrough of the release strand juncture or “u-turn” 656.As the operator pulls the release strand 653 out of the well 651, theconstraint or gap 652 prevents the opposing portions 654 and 655 of therelease strand 653 from crossing into the other side of the well 651.Said another way, the constraint or gap 652 keeps the juncture or“u-turn” 656 within its vicinity to facilitate an orderly withdrawal ofthe release strand 653 from the well 651. In this embodiment, therelease strand 653 can have a diameter of between about 0.004 and 0.010inch; specifically between about 0.006 and 0.007 inch. The gap orconstraint 652 should be between about 0.003 and about 0.009 inch;preferably between about 0.005 and about 0.006 inch.

[0254] Yet another variation of this embodiment, shown in FIG. 57,includes a post 661 disposed in a well 652 around which the releasestrand 663 is wound such that as the operator pulls the distal portion664 of the release strand 663 out of the distal end 665 of the well 652,the release strand 663 unwinds in an orderly fashion from the post 661.The post 661 may be optionally configured to spin on its longitudinalaxis, similar to that of a fishing reel spinner, to facilitate the exitof the release strand 663.

[0255] Other variations, such as a block and tackle arrangement (notshown), are envisioned in which the release strand 663 is looped througha grommet or similar feature. The grommet provides the necessaryfriction to prevent the entire release strand 663 from pulling out ofthe well 652 in one mass as soon as the operator applies a force on adistal end thereof. Any arrangement in which a frictional or similarforce is utilized to allow for the orderly dispensation of the releasestrand 663 from the shaft or post 661 is within the scope of theembodiment contemplated.

[0256]FIG. 58 depicts an optional hinged design for the belt supportmembers that is particularly useful for deploying the bifurcatedstent-graft in tortuous and/or angled anatomies, although it may be usedin all anatomies. Bifurcated graft 401 is depicted in phantom forreference. A hinge body 700 is affixed to guide wire tube 436 or primarybelt support member 452. Aperture 702 disposed on one side of primarybelt support member 452 is configured to receive hinge attachment member704, which in this embodiment is a wire that is looped through aperture702 and fixed to secondary belt support member 454. The hinge created ataperture 702 allows support member 454 to swing away from and towardsprimary belt support member 452 in the direction indicated by arrows 708in FIG. 58.

[0257] As shown in FIG. 58, aperture 702 is disposed on the side ofprimary belt support member 452 opposite that on which secondary beltsupport member 454 resides to facilitate extraction of the belt supportmembers from the graft and the patient's body after graft deployment.However, aperture 702 may also be disposed on the same side of primarybelt support member 452 as that of secondary belt support member 454 orin any suitable orientation around member 452.

[0258] Release strand 710 is affixed to release strand attachment member706 at secondary belt support member proximal end 714 and is preferablya stainless steel wire having a diameter of between about 0.004 inch and0.010 inch, although other materials and diameters may be used.Secondary belt 716 is shown disposed on support member 454 along withoptional silicone tubing 711.

[0259] Chiefly in tortuous or angled anatomies, but also in straightervessels, it is useful to allow for a degree of slack in thecontralateral limb 405 to be loaded into the elongate shaft 423. Suchslack helps the contralateral leg 405 negotiate various bends in theiliac and/or femoral arteries. The total amount of slack ΔI ideallynecessary for a graft limb such as limb 405 to negotiate an angle dΔΘ isrepresented by the equation:

ΔI=dΔΘ

[0260] “ΔΘ” is the cumulative angle change (the sum of the absolutevalue of the angles through which the limb must negotiate) along itslength, measured in radians, and where “d” is the diameter of the graftlimb.

[0261] The hinge design of FIG. 58 allows the necessary amount of slackΔI to be maintained in the contralateral leg 405 both during the step ofloading graft 401 in shaft 423 and during graft deployment andplacement. Note that in an embodiment of the present invention, apredetermined amount of slack may also be built into the ipsilateral leg404 as it is assembled for delivery. By building a predetermined amountof slack in each of the legs of graft 401, the most prevalent patientanatomies may, for instance, be targeted so that the average graftdelivery procedure will require the smallest amount of leg adjustment ormanipulation by the operator.

[0262] After graft 401 has been deployed, the apparatus of FIG. 58 isnext withdrawn from the graft and the patient's vasculature in thedirection of arrows 712 as shown in FIG. 59 over guide wire 530. Duringthis withdrawal, secondary belt support member 454 rotates aboutaperture 702 and pivots towards primary belt support member 452 in thedirection of arrow 713. An optional buttress may be employed asdescribed later to facilitate the withdrawal process.

[0263] Both primary and secondary belt support members are ideallyradiopaque to facilitate withdrawal from the vasculature. Secondary beltsupport member 454 and hinge attachment member 704 should be flexibleenough to turn the corner around graft bifurcation 406 with little or nopermanent deformation as the operator withdraws the primary belt supportmember 452 in the direction of arrows 712.

[0264] Withdrawal of member 452 causes secondary belt support member 454to first retreat from contralateral limb 405 until the proximal end 714of secondary belt support member 454 clears the graft walls in thevicinity of bifurcation 406, allowing the hinge to further act to alignsecondary belt support member in a generally parallel relationship withprimary belt support member 452 as both are then withdrawn through theipsilateral leg 404 and eventually out of the patient's body throughright femoral access hole 531. Release strand 710 follows secondary beltsupport member 454 out of the body.

[0265] FIGS. 59A-B depict a variation of this hinge design that limitsrotation of the secondary belt support member 454 to a single plane.Here, hinge body 732 is fixedly disposed on a distal portion 451 ofprimary belt support member 452 and comprises an offset flanged pin 734or like element. Pin 734 is disposed in an aperture 736 that runsthrough the distal end 508 of secondary belt support member 454 andhinge body 732. In this configuration, secondary belt support member 454is rotatably secured to pin 734 by optional flange 738 and is free torotate about pin 734 in the direction indicated by arrows 740 tofacilitate withdrawal of the delivery apparatus from the patient. Theoptional offset feature of pin 734 assists in the extraction of the beltsupport members from the graft and the Patient's body after graftdeployment.

[0266]FIG. 60 shows a close up partial cross-sectional view of theproximal end 417 of graft contralateral leg 405 disposed on the FIGS.58-59 (or alternatively FIG. 59A-B) secondary belt support member 454.Release strand tube 718, part of secondary release cable 721, housesrelease strand 710, a secondary release wire 719 (which holds secondarybelt 716 around contralateral proximal self expanding member 408), and ashield line 720 that is fixedly attached at its distal end 722 tooptional contralateral self-expanding member shield 724.

[0267] Optional expanding member shield 724 comprises PET or similarpolymeric material. Shield 724 acts as a shroud to cover proximalself-expanding member 408, protecting ipsilateral leg 404 from beingdamaged by self-expanding member 408 during delivery system assembly andgraft deployment. Further, shield 724 prevents direct contact betweencontralateral self-expanding member 408 and ipsilateral self-expandingmember 407, keeping the various self expanding member components fromsnaring one another or otherwise getting entangled. The exact positionof graft contralateral proximal self-expanding member 408 relative tograft ipsilateral leg 404 and self-expanding member 407 will depend onseveral factors, one of which is the degree of slack built into thegraft legs 404, 405 on members 452 and 454.

[0268] Shield 724 may be removed prior to retraction of secondaryrelease wire 719 by retracting shield line 720 in the directionindicated by arrow 729, typically after release strand tube 718 has beenremoved, and ultimately out of the patient's body through left femoralartery access hole 537. As shield 724 is retracted, release strand 710and secondary release wire 719 pass through wire apertures 728 and 730,respectively. Alternatively, a single wire aperture may be disposed onshield 724 through which both release strand 710 and secondary releasewire 719 pass.

[0269] A variation in the deployment sequence that may be used with anyof the sequences and equipment described above may be appropriate incertain clinical settings when the patient's vasculature exhibits adegree of tortuosity and/or angulation.

[0270] Related to the cuff and channel lumen patency matter discussedabove are at least two additional considerations when deploying a devicesuch as bifurcated graft 401 in tortuous or angled anatomies. First, itcan be more challenging to maintain the patency of either or both theblood flow passageways formed by the walls of graft contralateral leg405 and/or ipsilateral leg 404. Such challenges may also be presented inthe blood flow passageways defined by graft main body 402 of thebifurcated graft 401 and tubular graft 11 embodiments. This may in turnnegatively affect the patency of the cuff and channel lumens such thatthe cuffs and channels cannot adequately be filled with inflationmaterial. Second, the outer tubular member 431 can be more difficult toretract proximally relative to inner tubular member 430 when thedelivery system 400 is disposed in such angled and/or tortuousanatomies.

[0271] The delivery method discussed with respect to FIGS. 34-50 teachesthat the steps of deploying the distal and proximal self-expandingmembers are accomplished prior to the step of inflating the graft cuffsand channels. A variation in this deployment sequence that is useful fortortuous or angled patient anatomies is discussed below in conjunctionwith the delivery system components of FIGS. 31A, 31B and 58-60,although any of the delivery systems or their components describedherein may employ this sequence variation.

[0272] During the delivery procedure, after the first and second distalself expanding members 411 and 412 have been released, the operatorremoves release strand tube 718 from the body through the left femoralaccess hole 537. This exposes release strand 710, secondary release wire719, and shield line 720.

[0273] Next, the shield line 720 is pulled in a proximal direction 729by the operator to remove shield 724 from the contralateral leg proximalend 417, exposing self-expanding member 408. A buttress, which can be atubular member such as a catheter or the like, is threaded on theremaining secondary release wire 719 and release strand 710 and advanceddistally until it physically abuts the proximal end 483 of the secondarybelt support member 454. This provides a relatively stiff column thatthe operator may use to move the graft contralateral leq 405 in a distaldirection as well as react the force necessary to deploy self-expandingmember 408 by retracting release wire 719.

[0274] The operator next detaches Luer-type fitting or cap 521 fromflexible fill catheter 523 and removes ripcord 510 from channel 418.Graft 401 cuffs and channels may then be filled with inflation materialas previously described. When the inflation material is radiopaque orotherwise observable in vivo, the operator may interrogate the shape ofthe graft 401 and the various cuffs and channels under fluoroscopy orother suitable imaging technique to determine qraft limb patency, thesufficiency of graft cuff and channel inflation, and whether any foldsor other irregularities in the graft exist so that they may becorrected. When observed under fluoroscopy, the operator may adjust theC-arm of the fluoroscope to interrogate graft 401 from a number ofangles.

[0275] If necessary, and after cuff and channel inflation but beforeproximal self-expanding member deployment, the operator may manipulateboth the buttress catheter and/or release strand 710 to push or pull,respectively, the qraft contralateral leq into. the proper position. Bymaking fine adjustments in either direction, the operator may remove oradd slack in the graft contralateral leg 405 and ensure optimal qraftplacement and patency. To minimize operator confusion, the releasestrand 710 and stent release wire 719 may be different lenqths, colorcoded, flagged or otherwise labeled, etc. We have found that making thestent release wire 719 shorter than release strand 710 helps inmaintaining optimal operator orientation with respect to the variouscomponents of the qraft delivery system.

[0276] When the operator is satisfied with the position, patency, andappearance of graft 401, contralateral self-expanding member 408 may bedeployed by applying tension in the proximal direction 729 on secondaryrelease wire 719 so that secondary belt 716 releases proximalself-expanding member 408 in the manner previously described.

[0277] Similarly, the operator next may adjust the position of theipsilateral leg 404 of graft 401 by adjusting the position of primarybelt support member 452 and then release proximal self-expanding member407 of the ipsilateral leg 404 as described herein.

[0278] To withdraw the delivery apparatus, guide wire 530 is partiallywithdrawn in the proximal direction through nosepiece 434 into guidewire tube 436 to a point proximal of cuff 413. This prevents the guidewire 530 from possible interference with proper inflation of cuff 413.Next, the distal end 487 of the inflation tube 444 may be disengagedfrom the inflation port 421 by pulling on a proximal end 491 ofretention wire 488 as previously discussed. Using the buttress to pushon belt support member proximal portion 483 if necessary, the operatormay then proximally withdraw the primary belt support member 452 overguide wire 530 with the secondary belt support member 454 following.Finally, guide wire 530 is removed through left and right femoral accessholes 537, 531, which may then be repaired using conventionaltechniques.

[0279] It is clear to those of skill in the art that although particulartechniques and steps are described herein that we have found to beuseful, variations in the order and techniques in which the variousdeployment steps described herein are within the scope of the presentinvention.

[0280] While particular forms of the invention have been illustrated anddescribed, it will be apparent that various modifications can be madewithout departing from the spirit and scope of the invention.Accordingly, it is not intended that the invention be so limited.

We claim the following:
 1. A delivery system for a bifurcatedintracorporeal device comprising: an elongate shaft having a proximalsection and a distal section with the distal section comprising: anelongate primary belt support member; at least one primary belt securedto the primary belt support member configured to be circumferentiallydisposed about a bifurcated intracorporeal device so to at leastpartially constrain the device; a primary release member configured toengage and releasably secure the primary belt in a constrainingconfiguration; at least one elongate secondary belt support memberdisposed adjacent the elongate primary belt support member and securedto the primary belt support member with a releasable hinged joint; atleast one secondary belt secured to the secondary belt support memberconfigured to be circumferentially disposed about a bifurcatedintracorporeal device so to at least partially constrain the device; anda secondary release member configured to engage and releasably securethe secondary belt in a constraining configuration.